<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - edit/012-editor-undo.mu</title>
<meta name="Generator" content="Vim/7.4">
<meta name="plugin-version" content="vim7.4_v2">
<meta name="syntax" content="none">
<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #aaaaaa; background-color: #080808; }
body { font-size: 12pt; font-family: monospace; color: #aaaaaa; background-color: #080808; }
a { color:#eeeeee; text-decoration: none; }
a:hover { text-decoration: underline; }
* { font-size: 12pt; font-size: 1em; }
.Conceal { color: #4e4e4e; }
.muRecipe { color: #ff8700; }
.Special { color: #c00000; }
.Delimiter { color: #800080; }
.SalientComment { color: #00ffff; }
.Constant { color: #00a0a0; }
.LineNr { color: #444444; }
.Comment { color: #9090ff; }
.Comment a { color:#0000ee; text-decoration:underline; }
.muControl { color: #c0a020; }
.muScenario { color: #00af00; }
.muData { color: #ffff00; }
-->
</style>
<script type='text/javascript'>
<!--
/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
var lineNum;
lineNum = window.location.hash;
lineNum = lineNum.substr(1); /* strip off '#' */
if (lineNum.indexOf('L') == -1) {
lineNum = 'L'+lineNum;
}
lineElem = document.getElementById(lineNum);
/* Always jump to new location even if the line was hidden inside a fold, or
* we corrected the raw number to a line ID.
*/
if (lineElem) {
lineElem.scrollIntoView(true);
}
return true;
}
if ('onhashchange' in window) {
window.onhashchange = JumpToLine;
}
-->
</script>
</head>
<body onload='JumpToLine();'>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="SalientComment">## undo/redo</span>
<span id="L2" class="LineNr"> 2 </span>
<span id="L3" class="LineNr"> 3 </span><span class="Comment"># for every undoable event, create a type of *operation* that contains all the</span>
<span id="L4" class="LineNr"> 4 </span><span class="Comment"># information needed to reverse it</span>
<span id="L5" class="LineNr"> 5 </span><span class="muData">exclusive-container</span> <a href='012-editor-undo.mu.html#L5'>operation</a> [
<span id="L6" class="LineNr"> 6 </span> typing:<a href='012-editor-undo.mu.html#L11'>insert-operation</a>
<span id="L7" class="LineNr"> 7 </span> move:<a href='012-editor-undo.mu.html#L26'>move-operation</a>
<span id="L8" class="LineNr"> 8 </span> delete:<a href='012-editor-undo.mu.html#L43'>delete-operation</a>
<span id="L9" class="LineNr"> 9 </span>]
<span id="L10" class="LineNr"> 10 </span>
<span id="L11" class="LineNr"> 11 </span><span class="muData">container</span> <a href='012-editor-undo.mu.html#L11'>insert-operation</a> [
<span id="L12" class="LineNr"> 12 </span> before-row:num
<span id="L13" class="LineNr"> 13 </span> before-column:num
<span id="L14" class="LineNr"> 14 </span> before-top-of-screen:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L15" class="LineNr"> 15 </span> after-row:num
<span id="L16" class="LineNr"> 16 </span> after-column:num
<span id="L17" class="LineNr"> 17 </span> after-top-of-screen:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L18" class="LineNr"> 18 </span> <span class="Comment"># inserted text is from 'insert-from' until 'insert-until'; list doesn't have to terminate</span>
<span id="L19" class="LineNr"> 19 </span> insert-from:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L20" class="LineNr"> 20 </span> insert-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L21" class="LineNr"> 21 </span> tag:num <span class="Comment"># event causing this operation; might be used to coalesce runs of similar events</span>
<span id="L22" class="LineNr"> 22 </span> <span class="Conceal">¦</span> <span class="Comment"># 0: no coalesce (enter+indent)</span>
<span id="L23" class="LineNr"> 23 </span> <span class="Conceal">¦</span> <span class="Comment"># 1: regular alphanumeric characters</span>
<span id="L24" class="LineNr"> 24 </span>]
<span id="L25" class="LineNr"> 25 </span>
<span id="L26" class="LineNr"> 26 </span><span class="muData">container</span> <a href='012-editor-undo.mu.html#L26'>move-operation</a> [
<span id="L27" class="LineNr"> 27 </span> before-row:num
<span id="L28" class="LineNr"> 28 </span> before-column:num
<span id="L29" class="LineNr"> 29 </span> before-top-of-screen:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L30" class="LineNr"> 30 </span> after-row:num
<span id="L31" class="LineNr"> 31 </span> after-column:num
<span id="L32" class="LineNr"> 32 </span> after-top-of-screen:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L33" class="LineNr"> 33 </span> tag:num <span class="Comment"># event causing this operation; might be used to coalesce runs of similar events</span>
<span id="L34" class="LineNr"> 34 </span> <span class="Conceal">¦</span> <span class="Comment"># 0: no coalesce (touch events, etc)</span>
<span id="L35" class="LineNr"> 35 </span> <span class="Conceal">¦</span> <span class="Comment"># 1: left arrow</span>
<span id="L36" class="LineNr"> 36 </span> <span class="Conceal">¦</span> <span class="Comment"># 2: right arrow</span>
<span id="L37" class="LineNr"> 37 </span> <span class="Conceal">¦</span> <span class="Comment"># 3: up arrow</span>
<span id="L38" class="LineNr"> 38 </span> <span class="Conceal">¦</span> <span class="Comment"># 4: down arrow</span>
<span id="L39" class="LineNr"> 39 </span> <span class="Conceal">¦</span> <span class="Comment"># 5: line up</span>
<span id="L40" class="LineNr"> 40 </span> <span class="Conceal">¦</span> <span class="Comment"># 6: line down</span>
<span id="L41" class="LineNr"> 41 </span>]
<span id="L42" class="LineNr"> 42 </span>
<span id="L43" class="LineNr"> 43 </span><span class="muData">container</span> <a href='012-editor-undo.mu.html#L43'>delete-operation</a> [
<span id="L44" class="LineNr"> 44 </span> before-row:num
<span id="L45" class="LineNr"> 45 </span> before-column:num
<span id="L46" class="LineNr"> 46 </span> before-top-of-screen:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L47" class="LineNr"> 47 </span> after-row:num
<span id="L48" class="LineNr"> 48 </span> after-column:num
<span id="L49" class="LineNr"> 49 </span> after-top-of-screen:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L50" class="LineNr"> 50 </span> deleted-text:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L51" class="LineNr"> 51 </span> delete-from:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L52" class="LineNr"> 52 </span> delete-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char
<span id="L53" class="LineNr"> 53 </span> tag:num <span class="Comment"># event causing this operation; might be used to coalesce runs of similar events</span>
<span id="L54" class="LineNr"> 54 </span> <span class="Conceal">¦</span> <span class="Comment"># 0: no coalesce (ctrl-k, ctrl-u)</span>
<span id="L55" class="LineNr"> 55 </span> <span class="Conceal">¦</span> <span class="Comment"># 1: backspace</span>
<span id="L56" class="LineNr"> 56 </span> <span class="Conceal">¦</span> <span class="Comment"># 2: delete</span>
<span id="L57" class="LineNr"> 57 </span>]
<span id="L58" class="LineNr"> 58 </span>
<span id="L59" class="LineNr"> 59 </span><span class="Comment"># every editor accumulates a list of operations to undo/redo</span>
<span id="L60" class="LineNr"> 60 </span><span class="muData">container</span> editor [
<span id="L61" class="LineNr"> 61 </span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a>
<span id="L62" class="LineNr"> 62 </span> redo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a>
<span id="L63" class="LineNr"> 63 </span>]
<span id="L64" class="LineNr"> 64 </span>
<span id="L65" class="LineNr"> 65 </span><span class="Comment"># ctrl-z - undo operation</span>
<span id="L66" class="LineNr"> 66 </span><span class="muRecipe">after</span> <span class="Constant"><a href='002-typing.mu.html#L185'><handle-special-character></a></span> [
<span id="L67" class="LineNr"> 67 </span> <span class="Delimiter">{</span>
<span id="L68" class="LineNr"> 68 </span> <span class="Conceal">¦</span> undo?:bool <span class="Special"><-</span> equal c, <span class="Constant">26/ctrl-z</span>
<span id="L69" class="LineNr"> 69 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo?
<span id="L70" class="LineNr"> 70 </span> <span class="Conceal">¦</span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L71" class="LineNr"> 71 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo
<span id="L72" class="LineNr"> 72 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> first undo
<span id="L73" class="LineNr"> 73 </span> <span class="Conceal">¦</span> undo <span class="Special"><-</span> <a href='../064list.mu.html#L25'>rest</a> undo
<span id="L74" class="LineNr"> 74 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">undo:offset</span>, undo
<span id="L75" class="LineNr"> 75 </span> <span class="Conceal">¦</span> redo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">redo:offset</span>
<span id="L76" class="LineNr"> 76 </span> <span class="Conceal">¦</span> redo <span class="Special"><-</span> push op, redo
<span id="L77" class="LineNr"> 77 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">redo:offset</span>, redo
<span id="L78" class="LineNr"> 78 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> <a href='012-editor-undo.mu.html#L78'><handle-undo></a></span>
<span id="L79" class="LineNr"> 79 </span> <span class="Conceal">¦</span> <span class="muControl">return</span> <span class="Constant">1/go-render</span>
<span id="L80" class="LineNr"> 80 </span> <span class="Delimiter">}</span>
<span id="L81" class="LineNr"> 81 </span>]
<span id="L82" class="LineNr"> 82 </span>
<span id="L83" class="LineNr"> 83 </span><span class="Comment"># ctrl-y - redo operation</span>
<span id="L84" class="LineNr"> 84 </span><span class="muRecipe">after</span> <span class="Constant"><a href='002-typing.mu.html#L185'><handle-special-character></a></span> [
<span id="L85" class="LineNr"> 85 </span> <span class="Delimiter">{</span>
<span id="L86" class="LineNr"> 86 </span> <span class="Conceal">¦</span> redo?:bool <span class="Special"><-</span> equal c, <span class="Constant">25/ctrl-y</span>
<span id="L87" class="LineNr"> 87 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> redo?
<span id="L88" class="LineNr"> 88 </span> <span class="Conceal">¦</span> redo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">redo:offset</span>
<span id="L89" class="LineNr"> 89 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> redo
<span id="L90" class="LineNr"> 90 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> first redo
<span id="L91" class="LineNr"> 91 </span> <span class="Conceal">¦</span> redo <span class="Special"><-</span> <a href='../064list.mu.html#L25'>rest</a> redo
<span id="L92" class="LineNr"> 92 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">redo:offset</span>, redo
<span id="L93" class="LineNr"> 93 </span> <span class="Conceal">¦</span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L94" class="LineNr"> 94 </span> <span class="Conceal">¦</span> undo <span class="Special"><-</span> push op, undo
<span id="L95" class="LineNr"> 95 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">undo:offset</span>, undo
<span id="L96" class="LineNr"> 96 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> <a href='012-editor-undo.mu.html#L96'><handle-redo></a></span>
<span id="L97" class="LineNr"> 97 </span> <span class="Conceal">¦</span> <span class="muControl">return</span> <span class="Constant">1/go-render</span>
<span id="L98" class="LineNr"> 98 </span> <span class="Delimiter">}</span>
<span id="L99" class="LineNr"> 99 </span>]
<span id="L100" class="LineNr"> 100 </span>
<span id="L101" class="LineNr"> 101 </span><span class="Comment"># undo typing</span>
<span id="L102" class="LineNr"> 102 </span>
<span id="L103" class="LineNr"> 103 </span><span class="muScenario">scenario</span> editor-can-undo-typing [
<span id="L104" class="LineNr"> 104 </span> <span class="Constant">local-scope</span>
<span id="L105" class="LineNr"> 105 </span> <span class="Comment"># create an editor and type a character</span>
<span id="L106" class="LineNr"> 106 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L107" class="LineNr"> 107 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L108" class="LineNr"> 108 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L109" class="LineNr"> 109 </span> assume-console [
<span id="L110" class="LineNr"> 110 </span> <span class="Conceal">¦</span> type <span class="Constant">[0]</span>
<span id="L111" class="LineNr"> 111 </span> ]
<span id="L112" class="LineNr"> 112 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L113" class="LineNr"> 113 </span> <span class="Comment"># undo</span>
<span id="L114" class="LineNr"> 114 </span> assume-console [
<span id="L115" class="LineNr"> 115 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L116" class="LineNr"> 116 </span> ]
<span id="L117" class="LineNr"> 117 </span> run [
<span id="L118" class="LineNr"> 118 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L119" class="LineNr"> 119 </span> ]
<span id="L120" class="LineNr"> 120 </span> <span class="Comment"># character should be gone</span>
<span id="L121" class="LineNr"> 121 </span> screen-should-contain [
<span id="L122" class="LineNr"> 122 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L123" class="LineNr"> 123 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L124" class="LineNr"> 124 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L125" class="LineNr"> 125 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L126" class="LineNr"> 126 </span> ]
<span id="L127" class="LineNr"> 127 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L128" class="LineNr"> 128 </span> assume-console [
<span id="L129" class="LineNr"> 129 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L130" class="LineNr"> 130 </span> ]
<span id="L131" class="LineNr"> 131 </span> run [
<span id="L132" class="LineNr"> 132 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L133" class="LineNr"> 133 </span> ]
<span id="L134" class="LineNr"> 134 </span> screen-should-contain [
<span id="L135" class="LineNr"> 135 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L136" class="LineNr"> 136 </span> <span class="Conceal">¦</span><span class="Constant"> .1 .</span>
<span id="L137" class="LineNr"> 137 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L138" class="LineNr"> 138 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L139" class="LineNr"> 139 </span> ]
<span id="L140" class="LineNr"> 140 </span>]
<span id="L141" class="LineNr"> 141 </span>
<span id="L142" class="LineNr"> 142 </span><span class="Comment"># save operation to undo</span>
<span id="L143" class="LineNr"> 143 </span><span class="muRecipe">after</span> <span class="Constant"><insert-character-begin></span> [
<span id="L144" class="LineNr"> 144 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L145" class="LineNr"> 145 </span> cursor-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L146" class="LineNr"> 146 </span>]
<span id="L147" class="LineNr"> 147 </span><span class="muRecipe">before</span> <span class="Constant"><insert-character-end></span> [
<span id="L148" class="LineNr"> 148 </span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L149" class="LineNr"> 149 </span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L150" class="LineNr"> 150 </span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-column:offset</span>
<span id="L151" class="LineNr"> 151 </span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L152" class="LineNr"> 152 </span> <span class="Delimiter">{</span>
<span id="L153" class="LineNr"> 153 </span> <span class="Conceal">¦</span> <span class="Comment"># if previous operation was an insert, coalesce this operation with it</span>
<span id="L154" class="LineNr"> 154 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo
<span id="L155" class="LineNr"> 155 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> first undo
<span id="L156" class="LineNr"> 156 </span> <span class="Conceal">¦</span> typing:<a href='012-editor-undo.mu.html#L11'>insert-operation</a>, is-insert?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">typing:variant</span>
<span id="L157" class="LineNr"> 157 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-insert?
<span id="L158" class="LineNr"> 158 </span> <span class="Conceal">¦</span> previous-coalesce-tag:num <span class="Special"><-</span> get typing, <span class="Constant">tag:offset</span>
<span id="L159" class="LineNr"> 159 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> previous-coalesce-tag
<span id="L160" class="LineNr"> 160 </span> <span class="Conceal">¦</span> before-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L161" class="LineNr"> 161 </span> <span class="Conceal">¦</span> insert-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L162" class="LineNr"> 162 </span> <span class="Conceal">¦</span> typing <span class="Special"><-</span> put typing, <span class="Constant">insert-until:offset</span>, insert-until
<span id="L163" class="LineNr"> 163 </span> <span class="Conceal">¦</span> typing <span class="Special"><-</span> put typing, <span class="Constant">after-row:offset</span>, cursor-row
<span id="L164" class="LineNr"> 164 </span> <span class="Conceal">¦</span> typing <span class="Special"><-</span> put typing, <span class="Constant">after-column:offset</span>, cursor-column
<span id="L165" class="LineNr"> 165 </span> <span class="Conceal">¦</span> typing <span class="Special"><-</span> put typing, <span class="Constant">after-top-of-screen:offset</span>, top-after
<span id="L166" class="LineNr"> 166 </span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">0/insert-operation</span>, typing
<span id="L167" class="LineNr"> 167 </span> <span class="Conceal">¦</span> <span class="muControl">break</span> <span class="Constant">+done-adding-insert-operation</span>
<span id="L168" class="LineNr"> 168 </span> <span class="Delimiter">}</span>
<span id="L169" class="LineNr"> 169 </span> <span class="Comment"># if not, create a new operation</span>
<span id="L170" class="LineNr"> 170 </span> insert-from:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> cursor-before
<span id="L171" class="LineNr"> 171 </span> insert-to:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> insert-from
<span id="L172" class="LineNr"> 172 </span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L173" class="LineNr"> 173 </span> *op <span class="Special"><-</span> merge <span class="Constant">0/insert-operation</span>, save-row/before, save-column/before, top-before, cursor-row/after, cursor-column/after, top-after, insert-from, insert-to, <span class="Constant">1/coalesce</span>
<span id="L174" class="LineNr"> 174 </span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L175" class="LineNr"> 175 </span><span class="Constant"> +done-adding-insert-operation</span>
<span id="L176" class="LineNr"> 176 </span>]
<span id="L177" class="LineNr"> 177 </span>
<span id="L178" class="LineNr"> 178 </span><span class="Comment"># enter operations never coalesce with typing before or after</span>
<span id="L179" class="LineNr"> 179 </span><span class="muRecipe">after</span> <span class="Constant"><a href='002-typing.mu.html#L861'><insert-enter-begin></a></span> [
<span id="L180" class="LineNr"> 180 </span> cursor-row-before:num <span class="Special"><-</span> copy cursor-row
<span id="L181" class="LineNr"> 181 </span> cursor-column-before:num <span class="Special"><-</span> copy cursor-column
<span id="L182" class="LineNr"> 182 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L183" class="LineNr"> 183 </span> cursor-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L184" class="LineNr"> 184 </span>]
<span id="L185" class="LineNr"> 185 </span><span class="muRecipe">before</span> <span class="Constant"><a href='002-typing.mu.html#L863'><insert-enter-end></a></span> [
<span id="L186" class="LineNr"> 186 </span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L187" class="LineNr"> 187 </span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L188" class="LineNr"> 188 </span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L189" class="LineNr"> 189 </span> <span class="Comment"># never coalesce</span>
<span id="L190" class="LineNr"> 190 </span> insert-from:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> cursor-before
<span id="L191" class="LineNr"> 191 </span> before-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L192" class="LineNr"> 192 </span> insert-to:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L193" class="LineNr"> 193 </span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L194" class="LineNr"> 194 </span> *op <span class="Special"><-</span> merge <span class="Constant">0/insert-operation</span>, cursor-row-before, cursor-column-before, top-before, cursor-row/after, cursor-column/after, top-after, insert-from, insert-to, <span class="Constant">0/never-coalesce</span>
<span id="L195" class="LineNr"> 195 </span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L196" class="LineNr"> 196 </span>]
<span id="L197" class="LineNr"> 197 </span>
<span id="L198" class="LineNr"> 198 </span><span class="Comment"># Everytime you add a new operation to the undo stack, be sure to clear the</span>
<span id="L199" class="LineNr"> 199 </span><span class="Comment"># redo stack, because it's now obsolete.</span>
<span id="L200" class="LineNr"> 200 </span><span class="Comment"># Beware: since we're counting cursor moves as operations, this means just</span>
<span id="L201" class="LineNr"> 201 </span><span class="Comment"># moving the cursor can lose work on the undo stack.</span>
<span id="L202" class="LineNr"> 202 </span><span class="muRecipe">def</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor:&:editor, op:&:<a href='012-editor-undo.mu.html#L5'>operation</a><span class="muRecipe"> -> </span>editor:&:editor [
<span id="L203" class="LineNr"> 203 </span> <span class="Constant">local-scope</span>
<span id="L204" class="LineNr"> 204 </span> <span class="Constant">load-ingredients</span>
<span id="L205" class="LineNr"> 205 </span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L206" class="LineNr"> 206 </span> undo <span class="Special"><-</span> push op undo
<span id="L207" class="LineNr"> 207 </span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">undo:offset</span>, undo
<span id="L208" class="LineNr"> 208 </span> redo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">redo:offset</span>
<span id="L209" class="LineNr"> 209 </span> redo <span class="Special"><-</span> copy<span class="Constant"> 0</span>
<span id="L210" class="LineNr"> 210 </span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">redo:offset</span>, redo
<span id="L211" class="LineNr"> 211 </span>]
<span id="L212" class="LineNr"> 212 </span>
<span id="L213" class="LineNr"> 213 </span><span class="muRecipe">after</span> <span class="Constant"><a href='012-editor-undo.mu.html#L78'><handle-undo></a></span> [
<span id="L214" class="LineNr"> 214 </span> <span class="Delimiter">{</span>
<span id="L215" class="LineNr"> 215 </span> <span class="Conceal">¦</span> typing:<a href='012-editor-undo.mu.html#L11'>insert-operation</a>, is-insert?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">typing:variant</span>
<span id="L216" class="LineNr"> 216 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-insert?
<span id="L217" class="LineNr"> 217 </span> <span class="Conceal">¦</span> start:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get typing, <span class="Constant">insert-from:offset</span>
<span id="L218" class="LineNr"> 218 </span> <span class="Conceal">¦</span> end:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get typing, <span class="Constant">insert-until:offset</span>
<span id="L219" class="LineNr"> 219 </span> <span class="Conceal">¦</span> <span class="Comment"># assert cursor-row/cursor-column/top-of-screen match after-row/after-column/after-top-of-screen</span>
<span id="L220" class="LineNr"> 220 </span> <span class="Conceal">¦</span> before-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L36'>prev</a> start
<span id="L221" class="LineNr"> 221 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">before-cursor:offset</span>, before-cursor
<span id="L222" class="LineNr"> 222 </span> <span class="Conceal">¦</span> <a href='../065duplex_list.mu.html#L389'>remove-between</a> before-cursor, end
<span id="L223" class="LineNr"> 223 </span> <span class="Conceal">¦</span> cursor-row <span class="Special"><-</span> get typing, <span class="Constant">before-row:offset</span>
<span id="L224" class="LineNr"> 224 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-row:offset</span>, cursor-row
<span id="L225" class="LineNr"> 225 </span> <span class="Conceal">¦</span> cursor-column <span class="Special"><-</span> get typing, <span class="Constant">before-column:offset</span>
<span id="L226" class="LineNr"> 226 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-column:offset</span>, cursor-column
<span id="L227" class="LineNr"> 227 </span> <span class="Conceal">¦</span> top:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get typing, <span class="Constant">before-top-of-screen:offset</span>
<span id="L228" class="LineNr"> 228 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">top-of-screen:offset</span>, top
<span id="L229" class="LineNr"> 229 </span> <span class="Delimiter">}</span>
<span id="L230" class="LineNr"> 230 </span>]
<span id="L231" class="LineNr"> 231 </span>
<span id="L232" class="LineNr"> 232 </span><span class="muScenario">scenario</span> editor-can-undo-typing-multiple [
<span id="L233" class="LineNr"> 233 </span> <span class="Constant">local-scope</span>
<span id="L234" class="LineNr"> 234 </span> <span class="Comment"># create an editor and type multiple characters</span>
<span id="L235" class="LineNr"> 235 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L236" class="LineNr"> 236 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L237" class="LineNr"> 237 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L238" class="LineNr"> 238 </span> assume-console [
<span id="L239" class="LineNr"> 239 </span> <span class="Conceal">¦</span> type <span class="Constant">[012]</span>
<span id="L240" class="LineNr"> 240 </span> ]
<span id="L241" class="LineNr"> 241 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L242" class="LineNr"> 242 </span> <span class="Comment"># undo</span>
<span id="L243" class="LineNr"> 243 </span> assume-console [
<span id="L244" class="LineNr"> 244 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L245" class="LineNr"> 245 </span> ]
<span id="L246" class="LineNr"> 246 </span> run [
<span id="L247" class="LineNr"> 247 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L248" class="LineNr"> 248 </span> ]
<span id="L249" class="LineNr"> 249 </span> <span class="Comment"># all characters must be gone</span>
<span id="L250" class="LineNr"> 250 </span> screen-should-contain [
<span id="L251" class="LineNr"> 251 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L252" class="LineNr"> 252 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L253" class="LineNr"> 253 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L254" class="LineNr"> 254 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L255" class="LineNr"> 255 </span> ]
<span id="L256" class="LineNr"> 256 </span>]
<span id="L257" class="LineNr"> 257 </span>
<span id="L258" class="LineNr"> 258 </span><span class="muScenario">scenario</span> editor-can-undo-typing-multiple-2 [
<span id="L259" class="LineNr"> 259 </span> <span class="Constant">local-scope</span>
<span id="L260" class="LineNr"> 260 </span> <span class="Comment"># create an editor with some text</span>
<span id="L261" class="LineNr"> 261 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L262" class="LineNr"> 262 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[a]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L263" class="LineNr"> 263 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L264" class="LineNr"> 264 </span> <span class="Comment"># type some characters</span>
<span id="L265" class="LineNr"> 265 </span> assume-console [
<span id="L266" class="LineNr"> 266 </span> <span class="Conceal">¦</span> type <span class="Constant">[012]</span>
<span id="L267" class="LineNr"> 267 </span> ]
<span id="L268" class="LineNr"> 268 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L269" class="LineNr"> 269 </span> screen-should-contain [
<span id="L270" class="LineNr"> 270 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L271" class="LineNr"> 271 </span> <span class="Conceal">¦</span><span class="Constant"> .012a .</span>
<span id="L272" class="LineNr"> 272 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L273" class="LineNr"> 273 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L274" class="LineNr"> 274 </span> ]
<span id="L275" class="LineNr"> 275 </span> <span class="Comment"># undo</span>
<span id="L276" class="LineNr"> 276 </span> assume-console [
<span id="L277" class="LineNr"> 277 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L278" class="LineNr"> 278 </span> ]
<span id="L279" class="LineNr"> 279 </span> run [
<span id="L280" class="LineNr"> 280 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L281" class="LineNr"> 281 </span> ]
<span id="L282" class="LineNr"> 282 </span> <span class="Comment"># back to original text</span>
<span id="L283" class="LineNr"> 283 </span> screen-should-contain [
<span id="L284" class="LineNr"> 284 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L285" class="LineNr"> 285 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L286" class="LineNr"> 286 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L287" class="LineNr"> 287 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L288" class="LineNr"> 288 </span> ]
<span id="L289" class="LineNr"> 289 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L290" class="LineNr"> 290 </span> assume-console [
<span id="L291" class="LineNr"> 291 </span> <span class="Conceal">¦</span> type <span class="Constant">[3]</span>
<span id="L292" class="LineNr"> 292 </span> ]
<span id="L293" class="LineNr"> 293 </span> run [
<span id="L294" class="LineNr"> 294 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L295" class="LineNr"> 295 </span> ]
<span id="L296" class="LineNr"> 296 </span> screen-should-contain [
<span id="L297" class="LineNr"> 297 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L298" class="LineNr"> 298 </span> <span class="Conceal">¦</span><span class="Constant"> .3a .</span>
<span id="L299" class="LineNr"> 299 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L300" class="LineNr"> 300 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L301" class="LineNr"> 301 </span> ]
<span id="L302" class="LineNr"> 302 </span>]
<span id="L303" class="LineNr"> 303 </span>
<span id="L304" class="LineNr"> 304 </span><span class="muScenario">scenario</span> editor-can-undo-typing-enter [
<span id="L305" class="LineNr"> 305 </span> <span class="Constant">local-scope</span>
<span id="L306" class="LineNr"> 306 </span> <span class="Comment"># create an editor with some text</span>
<span id="L307" class="LineNr"> 307 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L308" class="LineNr"> 308 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[ abc]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L309" class="LineNr"> 309 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L310" class="LineNr"> 310 </span> <span class="Comment"># new line</span>
<span id="L311" class="LineNr"> 311 </span> assume-console [
<span id="L312" class="LineNr"> 312 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 1</span>,<span class="Constant"> 8</span>
<span id="L313" class="LineNr"> 313 </span> <span class="Conceal">¦</span> press enter
<span id="L314" class="LineNr"> 314 </span> ]
<span id="L315" class="LineNr"> 315 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L316" class="LineNr"> 316 </span> screen-should-contain [
<span id="L317" class="LineNr"> 317 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L318" class="LineNr"> 318 </span> <span class="Conceal">¦</span><span class="Constant"> . abc .</span>
<span id="L319" class="LineNr"> 319 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L320" class="LineNr"> 320 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L321" class="LineNr"> 321 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L322" class="LineNr"> 322 </span> ]
<span id="L323" class="LineNr"> 323 </span> <span class="Comment"># line is indented</span>
<span id="L324" class="LineNr"> 324 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L325" class="LineNr"> 325 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L326" class="LineNr"> 326 </span> memory-should-contain [
<span id="L327" class="LineNr"> 327 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L328" class="LineNr"> 328 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L329" class="LineNr"> 329 </span> ]
<span id="L330" class="LineNr"> 330 </span> <span class="Comment"># undo</span>
<span id="L331" class="LineNr"> 331 </span> assume-console [
<span id="L332" class="LineNr"> 332 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L333" class="LineNr"> 333 </span> ]
<span id="L334" class="LineNr"> 334 </span> run [
<span id="L335" class="LineNr"> 335 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L336" class="LineNr"> 336 </span> ]
<span id="L337" class="LineNr"> 337 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L338" class="LineNr"> 338 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L339" class="LineNr"> 339 </span> memory-should-contain [
<span id="L340" class="LineNr"> 340 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L341" class="LineNr"> 341 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 5</span>
<span id="L342" class="LineNr"> 342 </span> ]
<span id="L343" class="LineNr"> 343 </span> <span class="Comment"># back to original text</span>
<span id="L344" class="LineNr"> 344 </span> screen-should-contain [
<span id="L345" class="LineNr"> 345 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L346" class="LineNr"> 346 </span> <span class="Conceal">¦</span><span class="Constant"> . abc .</span>
<span id="L347" class="LineNr"> 347 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L348" class="LineNr"> 348 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L349" class="LineNr"> 349 </span> ]
<span id="L350" class="LineNr"> 350 </span> <span class="Comment"># cursor should be at end of line</span>
<span id="L351" class="LineNr"> 351 </span> assume-console [
<span id="L352" class="LineNr"> 352 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L353" class="LineNr"> 353 </span> ]
<span id="L354" class="LineNr"> 354 </span> run [
<span id="L355" class="LineNr"> 355 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L356" class="LineNr"> 356 </span> ]
<span id="L357" class="LineNr"> 357 </span> screen-should-contain [
<span id="L358" class="LineNr"> 358 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L359" class="LineNr"> 359 </span> <span class="Conceal">¦</span><span class="Constant"> . abc1 .</span>
<span id="L360" class="LineNr"> 360 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L361" class="LineNr"> 361 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L362" class="LineNr"> 362 </span> ]
<span id="L363" class="LineNr"> 363 </span>]
<span id="L364" class="LineNr"> 364 </span>
<span id="L365" class="LineNr"> 365 </span><span class="Comment"># redo typing</span>
<span id="L366" class="LineNr"> 366 </span>
<span id="L367" class="LineNr"> 367 </span><span class="muScenario">scenario</span> editor-redo-typing [
<span id="L368" class="LineNr"> 368 </span> <span class="Constant">local-scope</span>
<span id="L369" class="LineNr"> 369 </span> <span class="Comment"># create an editor, type something, undo</span>
<span id="L370" class="LineNr"> 370 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L371" class="LineNr"> 371 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[a]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L372" class="LineNr"> 372 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L373" class="LineNr"> 373 </span> assume-console [
<span id="L374" class="LineNr"> 374 </span> <span class="Conceal">¦</span> type <span class="Constant">[012]</span>
<span id="L375" class="LineNr"> 375 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L376" class="LineNr"> 376 </span> ]
<span id="L377" class="LineNr"> 377 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L378" class="LineNr"> 378 </span> screen-should-contain [
<span id="L379" class="LineNr"> 379 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L380" class="LineNr"> 380 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L381" class="LineNr"> 381 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L382" class="LineNr"> 382 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L383" class="LineNr"> 383 </span> ]
<span id="L384" class="LineNr"> 384 </span> <span class="Comment"># redo</span>
<span id="L385" class="LineNr"> 385 </span> assume-console [
<span id="L386" class="LineNr"> 386 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L387" class="LineNr"> 387 </span> ]
<span id="L388" class="LineNr"> 388 </span> run [
<span id="L389" class="LineNr"> 389 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L390" class="LineNr"> 390 </span> ]
<span id="L391" class="LineNr"> 391 </span> <span class="Comment"># all characters must be back</span>
<span id="L392" class="LineNr"> 392 </span> screen-should-contain [
<span id="L393" class="LineNr"> 393 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L394" class="LineNr"> 394 </span> <span class="Conceal">¦</span><span class="Constant"> .012a .</span>
<span id="L395" class="LineNr"> 395 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L396" class="LineNr"> 396 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L397" class="LineNr"> 397 </span> ]
<span id="L398" class="LineNr"> 398 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L399" class="LineNr"> 399 </span> assume-console [
<span id="L400" class="LineNr"> 400 </span> <span class="Conceal">¦</span> type <span class="Constant">[3]</span>
<span id="L401" class="LineNr"> 401 </span> ]
<span id="L402" class="LineNr"> 402 </span> run [
<span id="L403" class="LineNr"> 403 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L404" class="LineNr"> 404 </span> ]
<span id="L405" class="LineNr"> 405 </span> screen-should-contain [
<span id="L406" class="LineNr"> 406 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L407" class="LineNr"> 407 </span> <span class="Conceal">¦</span><span class="Constant"> .0123a .</span>
<span id="L408" class="LineNr"> 408 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L409" class="LineNr"> 409 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L410" class="LineNr"> 410 </span> ]
<span id="L411" class="LineNr"> 411 </span>]
<span id="L412" class="LineNr"> 412 </span>
<span id="L413" class="LineNr"> 413 </span><span class="muRecipe">after</span> <span class="Constant"><a href='012-editor-undo.mu.html#L96'><handle-redo></a></span> [
<span id="L414" class="LineNr"> 414 </span> <span class="Delimiter">{</span>
<span id="L415" class="LineNr"> 415 </span> <span class="Conceal">¦</span> typing:<a href='012-editor-undo.mu.html#L11'>insert-operation</a>, is-insert?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">typing:variant</span>
<span id="L416" class="LineNr"> 416 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-insert?
<span id="L417" class="LineNr"> 417 </span> <span class="Conceal">¦</span> before-cursor <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L418" class="LineNr"> 418 </span> <span class="Conceal">¦</span> insert-from:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get typing, <span class="Constant">insert-from:offset</span> <span class="Comment"># ignore insert-to because it's already been spliced away</span>
<span id="L419" class="LineNr"> 419 </span> <span class="Conceal">¦</span> <span class="Comment"># assert insert-to matches next(before-cursor)</span>
<span id="L420" class="LineNr"> 420 </span> <span class="Conceal">¦</span> <a href='../065duplex_list.mu.html#L529'>splice</a> before-cursor, insert-from
<span id="L421" class="LineNr"> 421 </span> <span class="Conceal">¦</span> <span class="Comment"># assert cursor-row/cursor-column/top-of-screen match after-row/after-column/after-top-of-screen</span>
<span id="L422" class="LineNr"> 422 </span> <span class="Conceal">¦</span> cursor-row <span class="Special"><-</span> get typing, <span class="Constant">after-row:offset</span>
<span id="L423" class="LineNr"> 423 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-row:offset</span>, cursor-row
<span id="L424" class="LineNr"> 424 </span> <span class="Conceal">¦</span> cursor-column <span class="Special"><-</span> get typing, <span class="Constant">after-column:offset</span>
<span id="L425" class="LineNr"> 425 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-column:offset</span>, cursor-column
<span id="L426" class="LineNr"> 426 </span> <span class="Conceal">¦</span> top:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get typing, <span class="Constant">after-top-of-screen:offset</span>
<span id="L427" class="LineNr"> 427 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">top-of-screen:offset</span>, top
<span id="L428" class="LineNr"> 428 </span> <span class="Delimiter">}</span>
<span id="L429" class="LineNr"> 429 </span>]
<span id="L430" class="LineNr"> 430 </span>
<span id="L431" class="LineNr"> 431 </span><span class="muScenario">scenario</span> editor-redo-typing-empty [
<span id="L432" class="LineNr"> 432 </span> <span class="Constant">local-scope</span>
<span id="L433" class="LineNr"> 433 </span> <span class="Comment"># create an editor, type something, undo</span>
<span id="L434" class="LineNr"> 434 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L435" class="LineNr"> 435 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L436" class="LineNr"> 436 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L437" class="LineNr"> 437 </span> assume-console [
<span id="L438" class="LineNr"> 438 </span> <span class="Conceal">¦</span> type <span class="Constant">[012]</span>
<span id="L439" class="LineNr"> 439 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L440" class="LineNr"> 440 </span> ]
<span id="L441" class="LineNr"> 441 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L442" class="LineNr"> 442 </span> screen-should-contain [
<span id="L443" class="LineNr"> 443 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L444" class="LineNr"> 444 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L445" class="LineNr"> 445 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L446" class="LineNr"> 446 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L447" class="LineNr"> 447 </span> ]
<span id="L448" class="LineNr"> 448 </span> <span class="Comment"># redo</span>
<span id="L449" class="LineNr"> 449 </span> assume-console [
<span id="L450" class="LineNr"> 450 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L451" class="LineNr"> 451 </span> ]
<span id="L452" class="LineNr"> 452 </span> run [
<span id="L453" class="LineNr"> 453 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L454" class="LineNr"> 454 </span> ]
<span id="L455" class="LineNr"> 455 </span> <span class="Comment"># all characters must be back</span>
<span id="L456" class="LineNr"> 456 </span> screen-should-contain [
<span id="L457" class="LineNr"> 457 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L458" class="LineNr"> 458 </span> <span class="Conceal">¦</span><span class="Constant"> .012 .</span>
<span id="L459" class="LineNr"> 459 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L460" class="LineNr"> 460 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L461" class="LineNr"> 461 </span> ]
<span id="L462" class="LineNr"> 462 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L463" class="LineNr"> 463 </span> assume-console [
<span id="L464" class="LineNr"> 464 </span> <span class="Conceal">¦</span> type <span class="Constant">[3]</span>
<span id="L465" class="LineNr"> 465 </span> ]
<span id="L466" class="LineNr"> 466 </span> run [
<span id="L467" class="LineNr"> 467 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L468" class="LineNr"> 468 </span> ]
<span id="L469" class="LineNr"> 469 </span> screen-should-contain [
<span id="L470" class="LineNr"> 470 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L471" class="LineNr"> 471 </span> <span class="Conceal">¦</span><span class="Constant"> .0123 .</span>
<span id="L472" class="LineNr"> 472 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L473" class="LineNr"> 473 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L474" class="LineNr"> 474 </span> ]
<span id="L475" class="LineNr"> 475 </span>]
<span id="L476" class="LineNr"> 476 </span>
<span id="L477" class="LineNr"> 477 </span><span class="muScenario">scenario</span> editor-work-clears-redo-stack [
<span id="L478" class="LineNr"> 478 </span> <span class="Constant">local-scope</span>
<span id="L479" class="LineNr"> 479 </span> <span class="Comment"># create an editor with some text, do some work, undo</span>
<span id="L480" class="LineNr"> 480 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L481" class="LineNr"> 481 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L482" class="LineNr"> 482 </span><span class="Constant">def</span>
<span id="L483" class="LineNr"> 483 </span><span class="Constant">ghi]</span>
<span id="L484" class="LineNr"> 484 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L485" class="LineNr"> 485 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L486" class="LineNr"> 486 </span> assume-console [
<span id="L487" class="LineNr"> 487 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L488" class="LineNr"> 488 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L489" class="LineNr"> 489 </span> ]
<span id="L490" class="LineNr"> 490 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L491" class="LineNr"> 491 </span> <span class="Comment"># do some more work</span>
<span id="L492" class="LineNr"> 492 </span> assume-console [
<span id="L493" class="LineNr"> 493 </span> <span class="Conceal">¦</span> type <span class="Constant">[0]</span>
<span id="L494" class="LineNr"> 494 </span> ]
<span id="L495" class="LineNr"> 495 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L496" class="LineNr"> 496 </span> screen-should-contain [
<span id="L497" class="LineNr"> 497 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L498" class="LineNr"> 498 </span> <span class="Conceal">¦</span><span class="Constant"> .0abc .</span>
<span id="L499" class="LineNr"> 499 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L500" class="LineNr"> 500 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L501" class="LineNr"> 501 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L502" class="LineNr"> 502 </span> ]
<span id="L503" class="LineNr"> 503 </span> <span class="Comment"># redo</span>
<span id="L504" class="LineNr"> 504 </span> assume-console [
<span id="L505" class="LineNr"> 505 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L506" class="LineNr"> 506 </span> ]
<span id="L507" class="LineNr"> 507 </span> run [
<span id="L508" class="LineNr"> 508 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L509" class="LineNr"> 509 </span> ]
<span id="L510" class="LineNr"> 510 </span> <span class="Comment"># nothing should happen</span>
<span id="L511" class="LineNr"> 511 </span> screen-should-contain [
<span id="L512" class="LineNr"> 512 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L513" class="LineNr"> 513 </span> <span class="Conceal">¦</span><span class="Constant"> .0abc .</span>
<span id="L514" class="LineNr"> 514 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L515" class="LineNr"> 515 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L516" class="LineNr"> 516 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L517" class="LineNr"> 517 </span> ]
<span id="L518" class="LineNr"> 518 </span>]
<span id="L519" class="LineNr"> 519 </span>
<span id="L520" class="LineNr"> 520 </span><span class="muScenario">scenario</span> editor-can-redo-typing-and-enter-and-tab [
<span id="L521" class="LineNr"> 521 </span> <span class="Constant">local-scope</span>
<span id="L522" class="LineNr"> 522 </span> <span class="Comment"># create an editor</span>
<span id="L523" class="LineNr"> 523 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L524" class="LineNr"> 524 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L525" class="LineNr"> 525 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L526" class="LineNr"> 526 </span> <span class="Comment"># insert some text and tabs, hit enter, some more text and tabs</span>
<span id="L527" class="LineNr"> 527 </span> assume-console [
<span id="L528" class="LineNr"> 528 </span> <span class="Conceal">¦</span> press tab
<span id="L529" class="LineNr"> 529 </span> <span class="Conceal">¦</span> type <span class="Constant">[ab]</span>
<span id="L530" class="LineNr"> 530 </span> <span class="Conceal">¦</span> press tab
<span id="L531" class="LineNr"> 531 </span> <span class="Conceal">¦</span> type <span class="Constant">[cd]</span>
<span id="L532" class="LineNr"> 532 </span> <span class="Conceal">¦</span> press enter
<span id="L533" class="LineNr"> 533 </span> <span class="Conceal">¦</span> press tab
<span id="L534" class="LineNr"> 534 </span> <span class="Conceal">¦</span> type <span class="Constant">[efg]</span>
<span id="L535" class="LineNr"> 535 </span> ]
<span id="L536" class="LineNr"> 536 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L537" class="LineNr"> 537 </span> screen-should-contain [
<span id="L538" class="LineNr"> 538 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L539" class="LineNr"> 539 </span> <span class="Conceal">¦</span><span class="Constant"> . ab cd .</span>
<span id="L540" class="LineNr"> 540 </span> <span class="Conceal">¦</span><span class="Constant"> . efg .</span>
<span id="L541" class="LineNr"> 541 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L542" class="LineNr"> 542 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L543" class="LineNr"> 543 </span> ]
<span id="L544" class="LineNr"> 544 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L545" class="LineNr"> 545 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L546" class="LineNr"> 546 </span> memory-should-contain [
<span id="L547" class="LineNr"> 547 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L548" class="LineNr"> 548 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 7</span>
<span id="L549" class="LineNr"> 549 </span> ]
<span id="L550" class="LineNr"> 550 </span> <span class="Comment"># undo</span>
<span id="L551" class="LineNr"> 551 </span> assume-console [
<span id="L552" class="LineNr"> 552 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L553" class="LineNr"> 553 </span> ]
<span id="L554" class="LineNr"> 554 </span> run [
<span id="L555" class="LineNr"> 555 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L556" class="LineNr"> 556 </span> ]
<span id="L557" class="LineNr"> 557 </span> <span class="Comment"># typing in second line deleted, but not indent</span>
<span id="L558" class="LineNr"> 558 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L559" class="LineNr"> 559 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L560" class="LineNr"> 560 </span> memory-should-contain [
<span id="L561" class="LineNr"> 561 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L562" class="LineNr"> 562 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L563" class="LineNr"> 563 </span> ]
<span id="L564" class="LineNr"> 564 </span> screen-should-contain [
<span id="L565" class="LineNr"> 565 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L566" class="LineNr"> 566 </span> <span class="Conceal">¦</span><span class="Constant"> . ab cd .</span>
<span id="L567" class="LineNr"> 567 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L568" class="LineNr"> 568 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L569" class="LineNr"> 569 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L570" class="LineNr"> 570 </span> ]
<span id="L571" class="LineNr"> 571 </span> <span class="Comment"># undo again</span>
<span id="L572" class="LineNr"> 572 </span> assume-console [
<span id="L573" class="LineNr"> 573 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L574" class="LineNr"> 574 </span> ]
<span id="L575" class="LineNr"> 575 </span> run [
<span id="L576" class="LineNr"> 576 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L577" class="LineNr"> 577 </span> ]
<span id="L578" class="LineNr"> 578 </span> <span class="Comment"># indent and newline deleted</span>
<span id="L579" class="LineNr"> 579 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L580" class="LineNr"> 580 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L581" class="LineNr"> 581 </span> memory-should-contain [
<span id="L582" class="LineNr"> 582 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L583" class="LineNr"> 583 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 8</span>
<span id="L584" class="LineNr"> 584 </span> ]
<span id="L585" class="LineNr"> 585 </span> screen-should-contain [
<span id="L586" class="LineNr"> 586 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L587" class="LineNr"> 587 </span> <span class="Conceal">¦</span><span class="Constant"> . ab cd .</span>
<span id="L588" class="LineNr"> 588 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L589" class="LineNr"> 589 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L590" class="LineNr"> 590 </span> ]
<span id="L591" class="LineNr"> 591 </span> <span class="Comment"># undo again</span>
<span id="L592" class="LineNr"> 592 </span> assume-console [
<span id="L593" class="LineNr"> 593 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L594" class="LineNr"> 594 </span> ]
<span id="L595" class="LineNr"> 595 </span> run [
<span id="L596" class="LineNr"> 596 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L597" class="LineNr"> 597 </span> ]
<span id="L598" class="LineNr"> 598 </span> <span class="Comment"># empty screen</span>
<span id="L599" class="LineNr"> 599 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L600" class="LineNr"> 600 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L601" class="LineNr"> 601 </span> memory-should-contain [
<span id="L602" class="LineNr"> 602 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L603" class="LineNr"> 603 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 0</span>
<span id="L604" class="LineNr"> 604 </span> ]
<span id="L605" class="LineNr"> 605 </span> screen-should-contain [
<span id="L606" class="LineNr"> 606 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L607" class="LineNr"> 607 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L608" class="LineNr"> 608 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L609" class="LineNr"> 609 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L610" class="LineNr"> 610 </span> ]
<span id="L611" class="LineNr"> 611 </span> <span class="Comment"># redo</span>
<span id="L612" class="LineNr"> 612 </span> assume-console [
<span id="L613" class="LineNr"> 613 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L614" class="LineNr"> 614 </span> ]
<span id="L615" class="LineNr"> 615 </span> run [
<span id="L616" class="LineNr"> 616 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L617" class="LineNr"> 617 </span> ]
<span id="L618" class="LineNr"> 618 </span> <span class="Comment"># first line inserted</span>
<span id="L619" class="LineNr"> 619 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L620" class="LineNr"> 620 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L621" class="LineNr"> 621 </span> memory-should-contain [
<span id="L622" class="LineNr"> 622 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L623" class="LineNr"> 623 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 8</span>
<span id="L624" class="LineNr"> 624 </span> ]
<span id="L625" class="LineNr"> 625 </span> screen-should-contain [
<span id="L626" class="LineNr"> 626 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L627" class="LineNr"> 627 </span> <span class="Conceal">¦</span><span class="Constant"> . ab cd .</span>
<span id="L628" class="LineNr"> 628 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L629" class="LineNr"> 629 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L630" class="LineNr"> 630 </span> ]
<span id="L631" class="LineNr"> 631 </span> <span class="Comment"># redo again</span>
<span id="L632" class="LineNr"> 632 </span> assume-console [
<span id="L633" class="LineNr"> 633 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L634" class="LineNr"> 634 </span> ]
<span id="L635" class="LineNr"> 635 </span> run [
<span id="L636" class="LineNr"> 636 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L637" class="LineNr"> 637 </span> ]
<span id="L638" class="LineNr"> 638 </span> <span class="Comment"># newline and indent inserted</span>
<span id="L639" class="LineNr"> 639 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L640" class="LineNr"> 640 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L641" class="LineNr"> 641 </span> memory-should-contain [
<span id="L642" class="LineNr"> 642 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L643" class="LineNr"> 643 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L644" class="LineNr"> 644 </span> ]
<span id="L645" class="LineNr"> 645 </span> screen-should-contain [
<span id="L646" class="LineNr"> 646 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L647" class="LineNr"> 647 </span> <span class="Conceal">¦</span><span class="Constant"> . ab cd .</span>
<span id="L648" class="LineNr"> 648 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L649" class="LineNr"> 649 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L650" class="LineNr"> 650 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L651" class="LineNr"> 651 </span> ]
<span id="L652" class="LineNr"> 652 </span> <span class="Comment"># redo again</span>
<span id="L653" class="LineNr"> 653 </span> assume-console [
<span id="L654" class="LineNr"> 654 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L655" class="LineNr"> 655 </span> ]
<span id="L656" class="LineNr"> 656 </span> run [
<span id="L657" class="LineNr"> 657 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L658" class="LineNr"> 658 </span> ]
<span id="L659" class="LineNr"> 659 </span> <span class="Comment"># indent and newline deleted</span>
<span id="L660" class="LineNr"> 660 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L661" class="LineNr"> 661 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L662" class="LineNr"> 662 </span> memory-should-contain [
<span id="L663" class="LineNr"> 663 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L664" class="LineNr"> 664 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 7</span>
<span id="L665" class="LineNr"> 665 </span> ]
<span id="L666" class="LineNr"> 666 </span> screen-should-contain [
<span id="L667" class="LineNr"> 667 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L668" class="LineNr"> 668 </span> <span class="Conceal">¦</span><span class="Constant"> . ab cd .</span>
<span id="L669" class="LineNr"> 669 </span> <span class="Conceal">¦</span><span class="Constant"> . efg .</span>
<span id="L670" class="LineNr"> 670 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L671" class="LineNr"> 671 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L672" class="LineNr"> 672 </span> ]
<span id="L673" class="LineNr"> 673 </span>]
<span id="L674" class="LineNr"> 674 </span>
<span id="L675" class="LineNr"> 675 </span><span class="Comment"># undo cursor movement and scroll</span>
<span id="L676" class="LineNr"> 676 </span>
<span id="L677" class="LineNr"> 677 </span><span class="muScenario">scenario</span> editor-can-undo-touch [
<span id="L678" class="LineNr"> 678 </span> <span class="Constant">local-scope</span>
<span id="L679" class="LineNr"> 679 </span> <span class="Comment"># create an editor with some text</span>
<span id="L680" class="LineNr"> 680 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L681" class="LineNr"> 681 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L682" class="LineNr"> 682 </span><span class="Constant">def</span>
<span id="L683" class="LineNr"> 683 </span><span class="Constant">ghi]</span>
<span id="L684" class="LineNr"> 684 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L685" class="LineNr"> 685 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L686" class="LineNr"> 686 </span> <span class="Comment"># move the cursor</span>
<span id="L687" class="LineNr"> 687 </span> assume-console [
<span id="L688" class="LineNr"> 688 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 3</span>,<span class="Constant"> 1</span>
<span id="L689" class="LineNr"> 689 </span> ]
<span id="L690" class="LineNr"> 690 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L691" class="LineNr"> 691 </span> <span class="Comment"># undo</span>
<span id="L692" class="LineNr"> 692 </span> assume-console [
<span id="L693" class="LineNr"> 693 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L694" class="LineNr"> 694 </span> ]
<span id="L695" class="LineNr"> 695 </span> run [
<span id="L696" class="LineNr"> 696 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L697" class="LineNr"> 697 </span> ]
<span id="L698" class="LineNr"> 698 </span> <span class="Comment"># click undone</span>
<span id="L699" class="LineNr"> 699 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L700" class="LineNr"> 700 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L701" class="LineNr"> 701 </span> memory-should-contain [
<span id="L702" class="LineNr"> 702 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L703" class="LineNr"> 703 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 0</span>
<span id="L704" class="LineNr"> 704 </span> ]
<span id="L705" class="LineNr"> 705 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L706" class="LineNr"> 706 </span> assume-console [
<span id="L707" class="LineNr"> 707 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L708" class="LineNr"> 708 </span> ]
<span id="L709" class="LineNr"> 709 </span> run [
<span id="L710" class="LineNr"> 710 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L711" class="LineNr"> 711 </span> ]
<span id="L712" class="LineNr"> 712 </span> screen-should-contain [
<span id="L713" class="LineNr"> 713 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L714" class="LineNr"> 714 </span> <span class="Conceal">¦</span><span class="Constant"> .1abc .</span>
<span id="L715" class="LineNr"> 715 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L716" class="LineNr"> 716 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L717" class="LineNr"> 717 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L718" class="LineNr"> 718 </span> ]
<span id="L719" class="LineNr"> 719 </span>]
<span id="L720" class="LineNr"> 720 </span>
<span id="L721" class="LineNr"> 721 </span><span class="muRecipe">after</span> <span class="Constant"><move-cursor-begin></span> [
<span id="L722" class="LineNr"> 722 </span> cursor-row-before:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L723" class="LineNr"> 723 </span> cursor-column-before:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-column:offset</span>
<span id="L724" class="LineNr"> 724 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L725" class="LineNr"> 725 </span>]
<span id="L726" class="LineNr"> 726 </span><span class="muRecipe">before</span> <span class="Constant"><move-cursor-end></span> [
<span id="L727" class="LineNr"> 727 </span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L728" class="LineNr"> 728 </span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L729" class="LineNr"> 729 </span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-column:offset</span>
<span id="L730" class="LineNr"> 730 </span> <span class="Delimiter">{</span>
<span id="L731" class="LineNr"> 731 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo-coalesce-tag
<span id="L732" class="LineNr"> 732 </span> <span class="Conceal">¦</span> <span class="Comment"># if previous operation was also a move, and also had the same coalesce</span>
<span id="L733" class="LineNr"> 733 </span> <span class="Conceal">¦</span> <span class="Comment"># tag, coalesce with it</span>
<span id="L734" class="LineNr"> 734 </span> <span class="Conceal">¦</span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L735" class="LineNr"> 735 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo
<span id="L736" class="LineNr"> 736 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> first undo
<span id="L737" class="LineNr"> 737 </span> <span class="Conceal">¦</span> move:<a href='012-editor-undo.mu.html#L26'>move-operation</a>, is-move?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">move:variant</span>
<span id="L738" class="LineNr"> 738 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-move?
<span id="L739" class="LineNr"> 739 </span> <span class="Conceal">¦</span> previous-coalesce-tag:num <span class="Special"><-</span> get move, <span class="Constant">tag:offset</span>
<span id="L740" class="LineNr"> 740 </span> <span class="Conceal">¦</span> coalesce?:bool <span class="Special"><-</span> equal undo-coalesce-tag, previous-coalesce-tag
<span id="L741" class="LineNr"> 741 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> coalesce?
<span id="L742" class="LineNr"> 742 </span> <span class="Conceal">¦</span> move <span class="Special"><-</span> put move, <span class="Constant">after-row:offset</span>, cursor-row
<span id="L743" class="LineNr"> 743 </span> <span class="Conceal">¦</span> move <span class="Special"><-</span> put move, <span class="Constant">after-column:offset</span>, cursor-column
<span id="L744" class="LineNr"> 744 </span> <span class="Conceal">¦</span> move <span class="Special"><-</span> put move, <span class="Constant">after-top-of-screen:offset</span>, top-after
<span id="L745" class="LineNr"> 745 </span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">1/move-operation</span>, move
<span id="L746" class="LineNr"> 746 </span> <span class="Conceal">¦</span> <span class="muControl">break</span> <span class="Constant">+done-adding-move-operation</span>
<span id="L747" class="LineNr"> 747 </span> <span class="Delimiter">}</span>
<span id="L748" class="LineNr"> 748 </span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L749" class="LineNr"> 749 </span> *op <span class="Special"><-</span> merge <span class="Constant">1/move-operation</span>, cursor-row-before, cursor-column-before, top-before, cursor-row/after, cursor-column/after, top-after, undo-coalesce-tag
<span id="L750" class="LineNr"> 750 </span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L751" class="LineNr"> 751 </span><span class="Constant"> +done-adding-move-operation</span>
<span id="L752" class="LineNr"> 752 </span>]
<span id="L753" class="LineNr"> 753 </span>
<span id="L754" class="LineNr"> 754 </span><span class="muRecipe">after</span> <span class="Constant"><a href='012-editor-undo.mu.html#L78'><handle-undo></a></span> [
<span id="L755" class="LineNr"> 755 </span> <span class="Delimiter">{</span>
<span id="L756" class="LineNr"> 756 </span> <span class="Conceal">¦</span> move:<a href='012-editor-undo.mu.html#L26'>move-operation</a>, is-move?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">move:variant</span>
<span id="L757" class="LineNr"> 757 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-move?
<span id="L758" class="LineNr"> 758 </span> <span class="Conceal">¦</span> <span class="Comment"># assert cursor-row/cursor-column/top-of-screen match after-row/after-column/after-top-of-screen</span>
<span id="L759" class="LineNr"> 759 </span> <span class="Conceal">¦</span> cursor-row <span class="Special"><-</span> get move, <span class="Constant">before-row:offset</span>
<span id="L760" class="LineNr"> 760 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-row:offset</span>, cursor-row
<span id="L761" class="LineNr"> 761 </span> <span class="Conceal">¦</span> cursor-column <span class="Special"><-</span> get move, <span class="Constant">before-column:offset</span>
<span id="L762" class="LineNr"> 762 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-column:offset</span>, cursor-column
<span id="L763" class="LineNr"> 763 </span> <span class="Conceal">¦</span> top:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get move, <span class="Constant">before-top-of-screen:offset</span>
<span id="L764" class="LineNr"> 764 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">top-of-screen:offset</span>, top
<span id="L765" class="LineNr"> 765 </span> <span class="Delimiter">}</span>
<span id="L766" class="LineNr"> 766 </span>]
<span id="L767" class="LineNr"> 767 </span>
<span id="L768" class="LineNr"> 768 </span><span class="muScenario">scenario</span> editor-can-undo-scroll [
<span id="L769" class="LineNr"> 769 </span> <span class="Constant">local-scope</span>
<span id="L770" class="LineNr"> 770 </span> <span class="Comment"># screen has 1 line for menu + 3 lines</span>
<span id="L771" class="LineNr"> 771 </span> assume-screen <span class="Constant">5/width</span>, <span class="Constant">4/height</span>
<span id="L772" class="LineNr"> 772 </span> <span class="Comment"># editor contains a wrapped line</span>
<span id="L773" class="LineNr"> 773 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[a</span>
<span id="L774" class="LineNr"> 774 </span><span class="Constant">b</span>
<span id="L775" class="LineNr"> 775 </span><span class="Constant">cdefgh]</span>
<span id="L776" class="LineNr"> 776 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
<span id="L777" class="LineNr"> 777 </span> <span class="Comment"># position cursor at end of screen and try to move right</span>
<span id="L778" class="LineNr"> 778 </span> assume-console [
<span id="L779" class="LineNr"> 779 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 3</span>,<span class="Constant"> 3</span>
<span id="L780" class="LineNr"> 780 </span> <span class="Conceal">¦</span> press right-arrow
<span id="L781" class="LineNr"> 781 </span> ]
<span id="L782" class="LineNr"> 782 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L783" class="LineNr"> 783 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L784" class="LineNr"> 784 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L785" class="LineNr"> 785 </span> <span class="Comment"># screen scrolls</span>
<span id="L786" class="LineNr"> 786 </span> screen-should-contain [
<span id="L787" class="LineNr"> 787 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L788" class="LineNr"> 788 </span> <span class="Conceal">¦</span><span class="Constant"> .b .</span>
<span id="L789" class="LineNr"> 789 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .cdef↩.</span>
<span id="L790" class="LineNr"> 790 </span> <span class="Conceal">¦</span><span class="Constant"> .gh .</span>
<span id="L791" class="LineNr"> 791 </span> ]
<span id="L792" class="LineNr"> 792 </span> memory-should-contain [
<span id="L793" class="LineNr"> 793 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L794" class="LineNr"> 794 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 0</span>
<span id="L795" class="LineNr"> 795 </span> ]
<span id="L796" class="LineNr"> 796 </span> <span class="Comment"># undo</span>
<span id="L797" class="LineNr"> 797 </span> assume-console [
<span id="L798" class="LineNr"> 798 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L799" class="LineNr"> 799 </span> ]
<span id="L800" class="LineNr"> 800 </span> run [
<span id="L801" class="LineNr"> 801 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L802" class="LineNr"> 802 </span> ]
<span id="L803" class="LineNr"> 803 </span> <span class="Comment"># cursor moved back</span>
<span id="L804" class="LineNr"> 804 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L805" class="LineNr"> 805 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L806" class="LineNr"> 806 </span> memory-should-contain [
<span id="L807" class="LineNr"> 807 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L808" class="LineNr"> 808 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L809" class="LineNr"> 809 </span> ]
<span id="L810" class="LineNr"> 810 </span> <span class="Comment"># scroll undone</span>
<span id="L811" class="LineNr"> 811 </span> screen-should-contain [
<span id="L812" class="LineNr"> 812 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L813" class="LineNr"> 813 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L814" class="LineNr"> 814 </span> <span class="Conceal">¦</span><span class="Constant"> .b .</span>
<span id="L815" class="LineNr"> 815 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .cdef↩.</span>
<span id="L816" class="LineNr"> 816 </span> ]
<span id="L817" class="LineNr"> 817 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L818" class="LineNr"> 818 </span> assume-console [
<span id="L819" class="LineNr"> 819 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L820" class="LineNr"> 820 </span> ]
<span id="L821" class="LineNr"> 821 </span> run [
<span id="L822" class="LineNr"> 822 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L823" class="LineNr"> 823 </span> ]
<span id="L824" class="LineNr"> 824 </span> screen-should-contain [
<span id="L825" class="LineNr"> 825 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L826" class="LineNr"> 826 </span> <span class="Conceal">¦</span><span class="Constant"> .b .</span>
<span id="L827" class="LineNr"> 827 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .cde1↩.</span>
<span id="L828" class="LineNr"> 828 </span> <span class="Conceal">¦</span><span class="Constant"> .fgh .</span>
<span id="L829" class="LineNr"> 829 </span> ]
<span id="L830" class="LineNr"> 830 </span>]
<span id="L831" class="LineNr"> 831 </span>
<span id="L832" class="LineNr"> 832 </span><span class="muScenario">scenario</span> editor-can-undo-left-arrow [
<span id="L833" class="LineNr"> 833 </span> <span class="Constant">local-scope</span>
<span id="L834" class="LineNr"> 834 </span> <span class="Comment"># create an editor with some text</span>
<span id="L835" class="LineNr"> 835 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L836" class="LineNr"> 836 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L837" class="LineNr"> 837 </span><span class="Constant">def</span>
<span id="L838" class="LineNr"> 838 </span><span class="Constant">ghi]</span>
<span id="L839" class="LineNr"> 839 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L840" class="LineNr"> 840 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L841" class="LineNr"> 841 </span> <span class="Comment"># move the cursor</span>
<span id="L842" class="LineNr"> 842 </span> assume-console [
<span id="L843" class="LineNr"> 843 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 3</span>,<span class="Constant"> 1</span>
<span id="L844" class="LineNr"> 844 </span> <span class="Conceal">¦</span> press left-arrow
<span id="L845" class="LineNr"> 845 </span> ]
<span id="L846" class="LineNr"> 846 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L847" class="LineNr"> 847 </span> <span class="Comment"># undo</span>
<span id="L848" class="LineNr"> 848 </span> assume-console [
<span id="L849" class="LineNr"> 849 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L850" class="LineNr"> 850 </span> ]
<span id="L851" class="LineNr"> 851 </span> run [
<span id="L852" class="LineNr"> 852 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L853" class="LineNr"> 853 </span> ]
<span id="L854" class="LineNr"> 854 </span> <span class="Comment"># cursor moves back</span>
<span id="L855" class="LineNr"> 855 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L856" class="LineNr"> 856 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L857" class="LineNr"> 857 </span> memory-should-contain [
<span id="L858" class="LineNr"> 858 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L859" class="LineNr"> 859 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L860" class="LineNr"> 860 </span> ]
<span id="L861" class="LineNr"> 861 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L862" class="LineNr"> 862 </span> assume-console [
<span id="L863" class="LineNr"> 863 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L864" class="LineNr"> 864 </span> ]
<span id="L865" class="LineNr"> 865 </span> run [
<span id="L866" class="LineNr"> 866 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L867" class="LineNr"> 867 </span> ]
<span id="L868" class="LineNr"> 868 </span> screen-should-contain [
<span id="L869" class="LineNr"> 869 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L870" class="LineNr"> 870 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L871" class="LineNr"> 871 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L872" class="LineNr"> 872 </span> <span class="Conceal">¦</span><span class="Constant"> .g1hi .</span>
<span id="L873" class="LineNr"> 873 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L874" class="LineNr"> 874 </span> ]
<span id="L875" class="LineNr"> 875 </span>]
<span id="L876" class="LineNr"> 876 </span>
<span id="L877" class="LineNr"> 877 </span><span class="muScenario">scenario</span> editor-can-undo-up-arrow [
<span id="L878" class="LineNr"> 878 </span> <span class="Constant">local-scope</span>
<span id="L879" class="LineNr"> 879 </span> <span class="Comment"># create an editor with some text</span>
<span id="L880" class="LineNr"> 880 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L881" class="LineNr"> 881 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L882" class="LineNr"> 882 </span><span class="Constant">def</span>
<span id="L883" class="LineNr"> 883 </span><span class="Constant">ghi]</span>
<span id="L884" class="LineNr"> 884 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L885" class="LineNr"> 885 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L886" class="LineNr"> 886 </span> <span class="Comment"># move the cursor</span>
<span id="L887" class="LineNr"> 887 </span> assume-console [
<span id="L888" class="LineNr"> 888 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 3</span>,<span class="Constant"> 1</span>
<span id="L889" class="LineNr"> 889 </span> <span class="Conceal">¦</span> press up-arrow
<span id="L890" class="LineNr"> 890 </span> ]
<span id="L891" class="LineNr"> 891 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L892" class="LineNr"> 892 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L893" class="LineNr"> 893 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L894" class="LineNr"> 894 </span> memory-should-contain [
<span id="L895" class="LineNr"> 895 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L896" class="LineNr"> 896 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L897" class="LineNr"> 897 </span> ]
<span id="L898" class="LineNr"> 898 </span> <span class="Comment"># undo</span>
<span id="L899" class="LineNr"> 899 </span> assume-console [
<span id="L900" class="LineNr"> 900 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L901" class="LineNr"> 901 </span> ]
<span id="L902" class="LineNr"> 902 </span> run [
<span id="L903" class="LineNr"> 903 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L904" class="LineNr"> 904 </span> ]
<span id="L905" class="LineNr"> 905 </span> <span class="Comment"># cursor moves back</span>
<span id="L906" class="LineNr"> 906 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L907" class="LineNr"> 907 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L908" class="LineNr"> 908 </span> memory-should-contain [
<span id="L909" class="LineNr"> 909 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L910" class="LineNr"> 910 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L911" class="LineNr"> 911 </span> ]
<span id="L912" class="LineNr"> 912 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L913" class="LineNr"> 913 </span> assume-console [
<span id="L914" class="LineNr"> 914 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L915" class="LineNr"> 915 </span> ]
<span id="L916" class="LineNr"> 916 </span> run [
<span id="L917" class="LineNr"> 917 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L918" class="LineNr"> 918 </span> ]
<span id="L919" class="LineNr"> 919 </span> screen-should-contain [
<span id="L920" class="LineNr"> 920 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L921" class="LineNr"> 921 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L922" class="LineNr"> 922 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L923" class="LineNr"> 923 </span> <span class="Conceal">¦</span><span class="Constant"> .g1hi .</span>
<span id="L924" class="LineNr"> 924 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L925" class="LineNr"> 925 </span> ]
<span id="L926" class="LineNr"> 926 </span>]
<span id="L927" class="LineNr"> 927 </span>
<span id="L928" class="LineNr"> 928 </span><span class="muScenario">scenario</span> editor-can-undo-down-arrow [
<span id="L929" class="LineNr"> 929 </span> <span class="Constant">local-scope</span>
<span id="L930" class="LineNr"> 930 </span> <span class="Comment"># create an editor with some text</span>
<span id="L931" class="LineNr"> 931 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L932" class="LineNr"> 932 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L933" class="LineNr"> 933 </span><span class="Constant">def</span>
<span id="L934" class="LineNr"> 934 </span><span class="Constant">ghi]</span>
<span id="L935" class="LineNr"> 935 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L936" class="LineNr"> 936 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L937" class="LineNr"> 937 </span> <span class="Comment"># move the cursor</span>
<span id="L938" class="LineNr"> 938 </span> assume-console [
<span id="L939" class="LineNr"> 939 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 2</span>,<span class="Constant"> 1</span>
<span id="L940" class="LineNr"> 940 </span> <span class="Conceal">¦</span> press down-arrow
<span id="L941" class="LineNr"> 941 </span> ]
<span id="L942" class="LineNr"> 942 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L943" class="LineNr"> 943 </span> <span class="Comment"># undo</span>
<span id="L944" class="LineNr"> 944 </span> assume-console [
<span id="L945" class="LineNr"> 945 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L946" class="LineNr"> 946 </span> ]
<span id="L947" class="LineNr"> 947 </span> run [
<span id="L948" class="LineNr"> 948 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L949" class="LineNr"> 949 </span> ]
<span id="L950" class="LineNr"> 950 </span> <span class="Comment"># cursor moves back</span>
<span id="L951" class="LineNr"> 951 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L952" class="LineNr"> 952 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L953" class="LineNr"> 953 </span> memory-should-contain [
<span id="L954" class="LineNr"> 954 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L955" class="LineNr"> 955 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L956" class="LineNr"> 956 </span> ]
<span id="L957" class="LineNr"> 957 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L958" class="LineNr"> 958 </span> assume-console [
<span id="L959" class="LineNr"> 959 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L960" class="LineNr"> 960 </span> ]
<span id="L961" class="LineNr"> 961 </span> run [
<span id="L962" class="LineNr"> 962 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L963" class="LineNr"> 963 </span> ]
<span id="L964" class="LineNr"> 964 </span> screen-should-contain [
<span id="L965" class="LineNr"> 965 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L966" class="LineNr"> 966 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L967" class="LineNr"> 967 </span> <span class="Conceal">¦</span><span class="Constant"> .d1ef .</span>
<span id="L968" class="LineNr"> 968 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L969" class="LineNr"> 969 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L970" class="LineNr"> 970 </span> ]
<span id="L971" class="LineNr"> 971 </span>]
<span id="L972" class="LineNr"> 972 </span>
<span id="L973" class="LineNr"> 973 </span><span class="muScenario">scenario</span> editor-can-undo-ctrl-f [
<span id="L974" class="LineNr"> 974 </span> <span class="Constant">local-scope</span>
<span id="L975" class="LineNr"> 975 </span> <span class="Comment"># create an editor with multiple pages of text</span>
<span id="L976" class="LineNr"> 976 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L977" class="LineNr"> 977 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[a</span>
<span id="L978" class="LineNr"> 978 </span><span class="Constant">b</span>
<span id="L979" class="LineNr"> 979 </span><span class="Constant">c</span>
<span id="L980" class="LineNr"> 980 </span><span class="Constant">d</span>
<span id="L981" class="LineNr"> 981 </span><span class="Constant">e</span>
<span id="L982" class="LineNr"> 982 </span><span class="Constant">f]</span>
<span id="L983" class="LineNr"> 983 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L984" class="LineNr"> 984 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L985" class="LineNr"> 985 </span> <span class="Comment"># scroll the page</span>
<span id="L986" class="LineNr"> 986 </span> assume-console [
<span id="L987" class="LineNr"> 987 </span> <span class="Conceal">¦</span> press ctrl-f
<span id="L988" class="LineNr"> 988 </span> ]
<span id="L989" class="LineNr"> 989 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L990" class="LineNr"> 990 </span> <span class="Comment"># undo</span>
<span id="L991" class="LineNr"> 991 </span> assume-console [
<span id="L992" class="LineNr"> 992 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L993" class="LineNr"> 993 </span> ]
<span id="L994" class="LineNr"> 994 </span> run [
<span id="L995" class="LineNr"> 995 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L996" class="LineNr"> 996 </span> ]
<span id="L997" class="LineNr"> 997 </span> <span class="Comment"># screen should again show page 1</span>
<span id="L998" class="LineNr"> 998 </span> screen-should-contain [
<span id="L999" class="LineNr"> 999 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1000" class="LineNr">1000 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L1001" class="LineNr">1001 </span> <span class="Conceal">¦</span><span class="Constant"> .b .</span>
<span id="L1002" class="LineNr">1002 </span> <span class="Conceal">¦</span><span class="Constant"> .c .</span>
<span id="L1003" class="LineNr">1003 </span> <span class="Conceal">¦</span><span class="Constant"> .d .</span>
<span id="L1004" class="LineNr">1004 </span> ]
<span id="L1005" class="LineNr">1005 </span>]
<span id="L1006" class="LineNr">1006 </span>
<span id="L1007" class="LineNr">1007 </span><span class="muScenario">scenario</span> editor-can-undo-page-down [
<span id="L1008" class="LineNr">1008 </span> <span class="Constant">local-scope</span>
<span id="L1009" class="LineNr">1009 </span> <span class="Comment"># create an editor with multiple pages of text</span>
<span id="L1010" class="LineNr">1010 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1011" class="LineNr">1011 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[a</span>
<span id="L1012" class="LineNr">1012 </span><span class="Constant">b</span>
<span id="L1013" class="LineNr">1013 </span><span class="Constant">c</span>
<span id="L1014" class="LineNr">1014 </span><span class="Constant">d</span>
<span id="L1015" class="LineNr">1015 </span><span class="Constant">e</span>
<span id="L1016" class="LineNr">1016 </span><span class="Constant">f]</span>
<span id="L1017" class="LineNr">1017 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1018" class="LineNr">1018 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1019" class="LineNr">1019 </span> <span class="Comment"># scroll the page</span>
<span id="L1020" class="LineNr">1020 </span> assume-console [
<span id="L1021" class="LineNr">1021 </span> <span class="Conceal">¦</span> press <a href='003-shortcuts.mu.html#L2981'>page-down</a>
<span id="L1022" class="LineNr">1022 </span> ]
<span id="L1023" class="LineNr">1023 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1024" class="LineNr">1024 </span> <span class="Comment"># undo</span>
<span id="L1025" class="LineNr">1025 </span> assume-console [
<span id="L1026" class="LineNr">1026 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1027" class="LineNr">1027 </span> ]
<span id="L1028" class="LineNr">1028 </span> run [
<span id="L1029" class="LineNr">1029 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1030" class="LineNr">1030 </span> ]
<span id="L1031" class="LineNr">1031 </span> <span class="Comment"># screen should again show page 1</span>
<span id="L1032" class="LineNr">1032 </span> screen-should-contain [
<span id="L1033" class="LineNr">1033 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1034" class="LineNr">1034 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L1035" class="LineNr">1035 </span> <span class="Conceal">¦</span><span class="Constant"> .b .</span>
<span id="L1036" class="LineNr">1036 </span> <span class="Conceal">¦</span><span class="Constant"> .c .</span>
<span id="L1037" class="LineNr">1037 </span> <span class="Conceal">¦</span><span class="Constant"> .d .</span>
<span id="L1038" class="LineNr">1038 </span> ]
<span id="L1039" class="LineNr">1039 </span>]
<span id="L1040" class="LineNr">1040 </span>
<span id="L1041" class="LineNr">1041 </span><span class="muScenario">scenario</span> editor-can-undo-ctrl-b [
<span id="L1042" class="LineNr">1042 </span> <span class="Constant">local-scope</span>
<span id="L1043" class="LineNr">1043 </span> <span class="Comment"># create an editor with multiple pages of text</span>
<span id="L1044" class="LineNr">1044 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1045" class="LineNr">1045 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[a</span>
<span id="L1046" class="LineNr">1046 </span><span class="Constant">b</span>
<span id="L1047" class="LineNr">1047 </span><span class="Constant">c</span>
<span id="L1048" class="LineNr">1048 </span><span class="Constant">d</span>
<span id="L1049" class="LineNr">1049 </span><span class="Constant">e</span>
<span id="L1050" class="LineNr">1050 </span><span class="Constant">f]</span>
<span id="L1051" class="LineNr">1051 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1052" class="LineNr">1052 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1053" class="LineNr">1053 </span> <span class="Comment"># scroll the page down and up</span>
<span id="L1054" class="LineNr">1054 </span> assume-console [
<span id="L1055" class="LineNr">1055 </span> <span class="Conceal">¦</span> press <a href='003-shortcuts.mu.html#L2981'>page-down</a>
<span id="L1056" class="LineNr">1056 </span> <span class="Conceal">¦</span> press ctrl-b
<span id="L1057" class="LineNr">1057 </span> ]
<span id="L1058" class="LineNr">1058 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1059" class="LineNr">1059 </span> <span class="Comment"># undo</span>
<span id="L1060" class="LineNr">1060 </span> assume-console [
<span id="L1061" class="LineNr">1061 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1062" class="LineNr">1062 </span> ]
<span id="L1063" class="LineNr">1063 </span> run [
<span id="L1064" class="LineNr">1064 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1065" class="LineNr">1065 </span> ]
<span id="L1066" class="LineNr">1066 </span> <span class="Comment"># screen should again show page 2</span>
<span id="L1067" class="LineNr">1067 </span> screen-should-contain [
<span id="L1068" class="LineNr">1068 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1069" class="LineNr">1069 </span> <span class="Conceal">¦</span><span class="Constant"> .d .</span>
<span id="L1070" class="LineNr">1070 </span> <span class="Conceal">¦</span><span class="Constant"> .e .</span>
<span id="L1071" class="LineNr">1071 </span> <span class="Conceal">¦</span><span class="Constant"> .f .</span>
<span id="L1072" class="LineNr">1072 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1073" class="LineNr">1073 </span> ]
<span id="L1074" class="LineNr">1074 </span>]
<span id="L1075" class="LineNr">1075 </span>
<span id="L1076" class="LineNr">1076 </span><span class="muScenario">scenario</span> editor-can-undo-page-up [
<span id="L1077" class="LineNr">1077 </span> <span class="Constant">local-scope</span>
<span id="L1078" class="LineNr">1078 </span> <span class="Comment"># create an editor with multiple pages of text</span>
<span id="L1079" class="LineNr">1079 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1080" class="LineNr">1080 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[a</span>
<span id="L1081" class="LineNr">1081 </span><span class="Constant">b</span>
<span id="L1082" class="LineNr">1082 </span><span class="Constant">c</span>
<span id="L1083" class="LineNr">1083 </span><span class="Constant">d</span>
<span id="L1084" class="LineNr">1084 </span><span class="Constant">e</span>
<span id="L1085" class="LineNr">1085 </span><span class="Constant">f]</span>
<span id="L1086" class="LineNr">1086 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1087" class="LineNr">1087 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1088" class="LineNr">1088 </span> <span class="Comment"># scroll the page down and up</span>
<span id="L1089" class="LineNr">1089 </span> assume-console [
<span id="L1090" class="LineNr">1090 </span> <span class="Conceal">¦</span> press <a href='003-shortcuts.mu.html#L2981'>page-down</a>
<span id="L1091" class="LineNr">1091 </span> <span class="Conceal">¦</span> press <a href='003-shortcuts.mu.html#L3179'>page-up</a>
<span id="L1092" class="LineNr">1092 </span> ]
<span id="L1093" class="LineNr">1093 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1094" class="LineNr">1094 </span> <span class="Comment"># undo</span>
<span id="L1095" class="LineNr">1095 </span> assume-console [
<span id="L1096" class="LineNr">1096 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1097" class="LineNr">1097 </span> ]
<span id="L1098" class="LineNr">1098 </span> run [
<span id="L1099" class="LineNr">1099 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1100" class="LineNr">1100 </span> ]
<span id="L1101" class="LineNr">1101 </span> <span class="Comment"># screen should again show page 2</span>
<span id="L1102" class="LineNr">1102 </span> screen-should-contain [
<span id="L1103" class="LineNr">1103 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1104" class="LineNr">1104 </span> <span class="Conceal">¦</span><span class="Constant"> .d .</span>
<span id="L1105" class="LineNr">1105 </span> <span class="Conceal">¦</span><span class="Constant"> .e .</span>
<span id="L1106" class="LineNr">1106 </span> <span class="Conceal">¦</span><span class="Constant"> .f .</span>
<span id="L1107" class="LineNr">1107 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1108" class="LineNr">1108 </span> ]
<span id="L1109" class="LineNr">1109 </span>]
<span id="L1110" class="LineNr">1110 </span>
<span id="L1111" class="LineNr">1111 </span><span class="muScenario">scenario</span> editor-can-undo-ctrl-a [
<span id="L1112" class="LineNr">1112 </span> <span class="Constant">local-scope</span>
<span id="L1113" class="LineNr">1113 </span> <span class="Comment"># create an editor with some text</span>
<span id="L1114" class="LineNr">1114 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1115" class="LineNr">1115 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1116" class="LineNr">1116 </span><span class="Constant">def</span>
<span id="L1117" class="LineNr">1117 </span><span class="Constant">ghi]</span>
<span id="L1118" class="LineNr">1118 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1119" class="LineNr">1119 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1120" class="LineNr">1120 </span> <span class="Comment"># move the cursor, then to start of line</span>
<span id="L1121" class="LineNr">1121 </span> assume-console [
<span id="L1122" class="LineNr">1122 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 2</span>,<span class="Constant"> 1</span>
<span id="L1123" class="LineNr">1123 </span> <span class="Conceal">¦</span> press ctrl-a
<span id="L1124" class="LineNr">1124 </span> ]
<span id="L1125" class="LineNr">1125 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1126" class="LineNr">1126 </span> <span class="Comment"># undo</span>
<span id="L1127" class="LineNr">1127 </span> assume-console [
<span id="L1128" class="LineNr">1128 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1129" class="LineNr">1129 </span> ]
<span id="L1130" class="LineNr">1130 </span> run [
<span id="L1131" class="LineNr">1131 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1132" class="LineNr">1132 </span> ]
<span id="L1133" class="LineNr">1133 </span> <span class="Comment"># cursor moves back</span>
<span id="L1134" class="LineNr">1134 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1135" class="LineNr">1135 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1136" class="LineNr">1136 </span> memory-should-contain [
<span id="L1137" class="LineNr">1137 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1138" class="LineNr">1138 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1139" class="LineNr">1139 </span> ]
<span id="L1140" class="LineNr">1140 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L1141" class="LineNr">1141 </span> assume-console [
<span id="L1142" class="LineNr">1142 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L1143" class="LineNr">1143 </span> ]
<span id="L1144" class="LineNr">1144 </span> run [
<span id="L1145" class="LineNr">1145 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1146" class="LineNr">1146 </span> ]
<span id="L1147" class="LineNr">1147 </span> screen-should-contain [
<span id="L1148" class="LineNr">1148 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1149" class="LineNr">1149 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1150" class="LineNr">1150 </span> <span class="Conceal">¦</span><span class="Constant"> .d1ef .</span>
<span id="L1151" class="LineNr">1151 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L1152" class="LineNr">1152 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1153" class="LineNr">1153 </span> ]
<span id="L1154" class="LineNr">1154 </span>]
<span id="L1155" class="LineNr">1155 </span>
<span id="L1156" class="LineNr">1156 </span><span class="muScenario">scenario</span> editor-can-undo-home [
<span id="L1157" class="LineNr">1157 </span> <span class="Constant">local-scope</span>
<span id="L1158" class="LineNr">1158 </span> <span class="Comment"># create an editor with some text</span>
<span id="L1159" class="LineNr">1159 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1160" class="LineNr">1160 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1161" class="LineNr">1161 </span><span class="Constant">def</span>
<span id="L1162" class="LineNr">1162 </span><span class="Constant">ghi]</span>
<span id="L1163" class="LineNr">1163 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1164" class="LineNr">1164 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1165" class="LineNr">1165 </span> <span class="Comment"># move the cursor, then to start of line</span>
<span id="L1166" class="LineNr">1166 </span> assume-console [
<span id="L1167" class="LineNr">1167 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 2</span>,<span class="Constant"> 1</span>
<span id="L1168" class="LineNr">1168 </span> <span class="Conceal">¦</span> press home
<span id="L1169" class="LineNr">1169 </span> ]
<span id="L1170" class="LineNr">1170 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1171" class="LineNr">1171 </span> <span class="Comment"># undo</span>
<span id="L1172" class="LineNr">1172 </span> assume-console [
<span id="L1173" class="LineNr">1173 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1174" class="LineNr">1174 </span> ]
<span id="L1175" class="LineNr">1175 </span> run [
<span id="L1176" class="LineNr">1176 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1177" class="LineNr">1177 </span> ]
<span id="L1178" class="LineNr">1178 </span> <span class="Comment"># cursor moves back</span>
<span id="L1179" class="LineNr">1179 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1180" class="LineNr">1180 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1181" class="LineNr">1181 </span> memory-should-contain [
<span id="L1182" class="LineNr">1182 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1183" class="LineNr">1183 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1184" class="LineNr">1184 </span> ]
<span id="L1185" class="LineNr">1185 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L1186" class="LineNr">1186 </span> assume-console [
<span id="L1187" class="LineNr">1187 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L1188" class="LineNr">1188 </span> ]
<span id="L1189" class="LineNr">1189 </span> run [
<span id="L1190" class="LineNr">1190 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1191" class="LineNr">1191 </span> ]
<span id="L1192" class="LineNr">1192 </span> screen-should-contain [
<span id="L1193" class="LineNr">1193 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1194" class="LineNr">1194 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1195" class="LineNr">1195 </span> <span class="Conceal">¦</span><span class="Constant"> .d1ef .</span>
<span id="L1196" class="LineNr">1196 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L1197" class="LineNr">1197 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1198" class="LineNr">1198 </span> ]
<span id="L1199" class="LineNr">1199 </span>]
<span id="L1200" class="LineNr">1200 </span>
<span id="L1201" class="LineNr">1201 </span><span class="muScenario">scenario</span> editor-can-undo-ctrl-e [
<span id="L1202" class="LineNr">1202 </span> <span class="Constant">local-scope</span>
<span id="L1203" class="LineNr">1203 </span> <span class="Comment"># create an editor with some text</span>
<span id="L1204" class="LineNr">1204 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1205" class="LineNr">1205 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1206" class="LineNr">1206 </span><span class="Constant">def</span>
<span id="L1207" class="LineNr">1207 </span><span class="Constant">ghi]</span>
<span id="L1208" class="LineNr">1208 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1209" class="LineNr">1209 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1210" class="LineNr">1210 </span> <span class="Comment"># move the cursor, then to start of line</span>
<span id="L1211" class="LineNr">1211 </span> assume-console [
<span id="L1212" class="LineNr">1212 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 2</span>,<span class="Constant"> 1</span>
<span id="L1213" class="LineNr">1213 </span> <span class="Conceal">¦</span> press ctrl-e
<span id="L1214" class="LineNr">1214 </span> ]
<span id="L1215" class="LineNr">1215 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1216" class="LineNr">1216 </span> <span class="Comment"># undo</span>
<span id="L1217" class="LineNr">1217 </span> assume-console [
<span id="L1218" class="LineNr">1218 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1219" class="LineNr">1219 </span> ]
<span id="L1220" class="LineNr">1220 </span> run [
<span id="L1221" class="LineNr">1221 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1222" class="LineNr">1222 </span> ]
<span id="L1223" class="LineNr">1223 </span> <span class="Comment"># cursor moves back</span>
<span id="L1224" class="LineNr">1224 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1225" class="LineNr">1225 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1226" class="LineNr">1226 </span> memory-should-contain [
<span id="L1227" class="LineNr">1227 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1228" class="LineNr">1228 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1229" class="LineNr">1229 </span> ]
<span id="L1230" class="LineNr">1230 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L1231" class="LineNr">1231 </span> assume-console [
<span id="L1232" class="LineNr">1232 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L1233" class="LineNr">1233 </span> ]
<span id="L1234" class="LineNr">1234 </span> run [
<span id="L1235" class="LineNr">1235 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1236" class="LineNr">1236 </span> ]
<span id="L1237" class="LineNr">1237 </span> screen-should-contain [
<span id="L1238" class="LineNr">1238 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1239" class="LineNr">1239 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1240" class="LineNr">1240 </span> <span class="Conceal">¦</span><span class="Constant"> .d1ef .</span>
<span id="L1241" class="LineNr">1241 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L1242" class="LineNr">1242 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1243" class="LineNr">1243 </span> ]
<span id="L1244" class="LineNr">1244 </span>]
<span id="L1245" class="LineNr">1245 </span>
<span id="L1246" class="LineNr">1246 </span><span class="muScenario">scenario</span> editor-can-undo-end [
<span id="L1247" class="LineNr">1247 </span> <span class="Constant">local-scope</span>
<span id="L1248" class="LineNr">1248 </span> <span class="Comment"># create an editor with some text</span>
<span id="L1249" class="LineNr">1249 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1250" class="LineNr">1250 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1251" class="LineNr">1251 </span><span class="Constant">def</span>
<span id="L1252" class="LineNr">1252 </span><span class="Constant">ghi]</span>
<span id="L1253" class="LineNr">1253 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1254" class="LineNr">1254 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1255" class="LineNr">1255 </span> <span class="Comment"># move the cursor, then to start of line</span>
<span id="L1256" class="LineNr">1256 </span> assume-console [
<span id="L1257" class="LineNr">1257 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 2</span>,<span class="Constant"> 1</span>
<span id="L1258" class="LineNr">1258 </span> <span class="Conceal">¦</span> press end
<span id="L1259" class="LineNr">1259 </span> ]
<span id="L1260" class="LineNr">1260 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1261" class="LineNr">1261 </span> <span class="Comment"># undo</span>
<span id="L1262" class="LineNr">1262 </span> assume-console [
<span id="L1263" class="LineNr">1263 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1264" class="LineNr">1264 </span> ]
<span id="L1265" class="LineNr">1265 </span> run [
<span id="L1266" class="LineNr">1266 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1267" class="LineNr">1267 </span> ]
<span id="L1268" class="LineNr">1268 </span> <span class="Comment"># cursor moves back</span>
<span id="L1269" class="LineNr">1269 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1270" class="LineNr">1270 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1271" class="LineNr">1271 </span> memory-should-contain [
<span id="L1272" class="LineNr">1272 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1273" class="LineNr">1273 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1274" class="LineNr">1274 </span> ]
<span id="L1275" class="LineNr">1275 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L1276" class="LineNr">1276 </span> assume-console [
<span id="L1277" class="LineNr">1277 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L1278" class="LineNr">1278 </span> ]
<span id="L1279" class="LineNr">1279 </span> run [
<span id="L1280" class="LineNr">1280 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1281" class="LineNr">1281 </span> ]
<span id="L1282" class="LineNr">1282 </span> screen-should-contain [
<span id="L1283" class="LineNr">1283 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1284" class="LineNr">1284 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1285" class="LineNr">1285 </span> <span class="Conceal">¦</span><span class="Constant"> .d1ef .</span>
<span id="L1286" class="LineNr">1286 </span> <span class="Conceal">¦</span><span class="Constant"> .ghi .</span>
<span id="L1287" class="LineNr">1287 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1288" class="LineNr">1288 </span> ]
<span id="L1289" class="LineNr">1289 </span>]
<span id="L1290" class="LineNr">1290 </span>
<span id="L1291" class="LineNr">1291 </span><span class="muScenario">scenario</span> editor-can-undo-multiple-arrows-in-the-same-direction [
<span id="L1292" class="LineNr">1292 </span> <span class="Constant">local-scope</span>
<span id="L1293" class="LineNr">1293 </span> <span class="Comment"># create an editor with some text</span>
<span id="L1294" class="LineNr">1294 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1295" class="LineNr">1295 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1296" class="LineNr">1296 </span><span class="Constant">def</span>
<span id="L1297" class="LineNr">1297 </span><span class="Constant">ghi]</span>
<span id="L1298" class="LineNr">1298 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1299" class="LineNr">1299 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1300" class="LineNr">1300 </span> <span class="Comment"># move the cursor</span>
<span id="L1301" class="LineNr">1301 </span> assume-console [
<span id="L1302" class="LineNr">1302 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 2</span>,<span class="Constant"> 1</span>
<span id="L1303" class="LineNr">1303 </span> <span class="Conceal">¦</span> press right-arrow
<span id="L1304" class="LineNr">1304 </span> <span class="Conceal">¦</span> press right-arrow
<span id="L1305" class="LineNr">1305 </span> <span class="Conceal">¦</span> press up-arrow
<span id="L1306" class="LineNr">1306 </span> ]
<span id="L1307" class="LineNr">1307 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1308" class="LineNr">1308 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1309" class="LineNr">1309 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1310" class="LineNr">1310 </span> memory-should-contain [
<span id="L1311" class="LineNr">1311 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1312" class="LineNr">1312 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L1313" class="LineNr">1313 </span> ]
<span id="L1314" class="LineNr">1314 </span> <span class="Comment"># undo</span>
<span id="L1315" class="LineNr">1315 </span> assume-console [
<span id="L1316" class="LineNr">1316 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1317" class="LineNr">1317 </span> ]
<span id="L1318" class="LineNr">1318 </span> run [
<span id="L1319" class="LineNr">1319 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1320" class="LineNr">1320 </span> ]
<span id="L1321" class="LineNr">1321 </span> <span class="Comment"># up-arrow is undone</span>
<span id="L1322" class="LineNr">1322 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1323" class="LineNr">1323 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1324" class="LineNr">1324 </span> memory-should-contain [
<span id="L1325" class="LineNr">1325 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1326" class="LineNr">1326 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L1327" class="LineNr">1327 </span> ]
<span id="L1328" class="LineNr">1328 </span> <span class="Comment"># undo again</span>
<span id="L1329" class="LineNr">1329 </span> assume-console [
<span id="L1330" class="LineNr">1330 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1331" class="LineNr">1331 </span> ]
<span id="L1332" class="LineNr">1332 </span> run [
<span id="L1333" class="LineNr">1333 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1334" class="LineNr">1334 </span> ]
<span id="L1335" class="LineNr">1335 </span> <span class="Comment"># both right-arrows are undone</span>
<span id="L1336" class="LineNr">1336 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1337" class="LineNr">1337 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1338" class="LineNr">1338 </span> memory-should-contain [
<span id="L1339" class="LineNr">1339 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1340" class="LineNr">1340 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1341" class="LineNr">1341 </span> ]
<span id="L1342" class="LineNr">1342 </span>]
<span id="L1343" class="LineNr">1343 </span>
<span id="L1344" class="LineNr">1344 </span><span class="Comment"># redo cursor movement and scroll</span>
<span id="L1345" class="LineNr">1345 </span>
<span id="L1346" class="LineNr">1346 </span><span class="muScenario">scenario</span> editor-redo-touch [
<span id="L1347" class="LineNr">1347 </span> <span class="Constant">local-scope</span>
<span id="L1348" class="LineNr">1348 </span> <span class="Comment"># create an editor with some text, click on a character, undo</span>
<span id="L1349" class="LineNr">1349 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1350" class="LineNr">1350 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1351" class="LineNr">1351 </span><span class="Constant">def</span>
<span id="L1352" class="LineNr">1352 </span><span class="Constant">ghi]</span>
<span id="L1353" class="LineNr">1353 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1354" class="LineNr">1354 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1355" class="LineNr">1355 </span> assume-console [
<span id="L1356" class="LineNr">1356 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 3</span>,<span class="Constant"> 1</span>
<span id="L1357" class="LineNr">1357 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1358" class="LineNr">1358 </span> ]
<span id="L1359" class="LineNr">1359 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1360" class="LineNr">1360 </span> <span class="Comment"># redo</span>
<span id="L1361" class="LineNr">1361 </span> assume-console [
<span id="L1362" class="LineNr">1362 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1363" class="LineNr">1363 </span> ]
<span id="L1364" class="LineNr">1364 </span> run [
<span id="L1365" class="LineNr">1365 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1366" class="LineNr">1366 </span> ]
<span id="L1367" class="LineNr">1367 </span> <span class="Comment"># cursor moves to left-click</span>
<span id="L1368" class="LineNr">1368 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1369" class="LineNr">1369 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1370" class="LineNr">1370 </span> memory-should-contain [
<span id="L1371" class="LineNr">1371 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L1372" class="LineNr">1372 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1373" class="LineNr">1373 </span> ]
<span id="L1374" class="LineNr">1374 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L1375" class="LineNr">1375 </span> assume-console [
<span id="L1376" class="LineNr">1376 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L1377" class="LineNr">1377 </span> ]
<span id="L1378" class="LineNr">1378 </span> run [
<span id="L1379" class="LineNr">1379 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1380" class="LineNr">1380 </span> ]
<span id="L1381" class="LineNr">1381 </span> screen-should-contain [
<span id="L1382" class="LineNr">1382 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1383" class="LineNr">1383 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1384" class="LineNr">1384 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L1385" class="LineNr">1385 </span> <span class="Conceal">¦</span><span class="Constant"> .g1hi .</span>
<span id="L1386" class="LineNr">1386 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1387" class="LineNr">1387 </span> ]
<span id="L1388" class="LineNr">1388 </span>]
<span id="L1389" class="LineNr">1389 </span>
<span id="L1390" class="LineNr">1390 </span><span class="muRecipe">after</span> <span class="Constant"><a href='012-editor-undo.mu.html#L96'><handle-redo></a></span> [
<span id="L1391" class="LineNr">1391 </span> <span class="Delimiter">{</span>
<span id="L1392" class="LineNr">1392 </span> <span class="Conceal">¦</span> move:<a href='012-editor-undo.mu.html#L26'>move-operation</a>, is-move?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">move:variant</span>
<span id="L1393" class="LineNr">1393 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-move?
<span id="L1394" class="LineNr">1394 </span> <span class="Conceal">¦</span> <span class="Comment"># assert cursor-row/cursor-column/top-of-screen match after-row/after-column/after-top-of-screen</span>
<span id="L1395" class="LineNr">1395 </span> <span class="Conceal">¦</span> cursor-row <span class="Special"><-</span> get move, <span class="Constant">after-row:offset</span>
<span id="L1396" class="LineNr">1396 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-row:offset</span>, cursor-row
<span id="L1397" class="LineNr">1397 </span> <span class="Conceal">¦</span> cursor-column <span class="Special"><-</span> get move, <span class="Constant">after-column:offset</span>
<span id="L1398" class="LineNr">1398 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-column:offset</span>, cursor-column
<span id="L1399" class="LineNr">1399 </span> <span class="Conceal">¦</span> top:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get move, <span class="Constant">after-top-of-screen:offset</span>
<span id="L1400" class="LineNr">1400 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">top-of-screen:offset</span>, top
<span id="L1401" class="LineNr">1401 </span> <span class="Delimiter">}</span>
<span id="L1402" class="LineNr">1402 </span>]
<span id="L1403" class="LineNr">1403 </span>
<span id="L1404" class="LineNr">1404 </span><span class="muScenario">scenario</span> editor-separates-undo-insert-from-undo-cursor-move [
<span id="L1405" class="LineNr">1405 </span> <span class="Constant">local-scope</span>
<span id="L1406" class="LineNr">1406 </span> <span class="Comment"># create an editor, type some text, move the cursor, type some more text</span>
<span id="L1407" class="LineNr">1407 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1408" class="LineNr">1408 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1409" class="LineNr">1409 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1410" class="LineNr">1410 </span> assume-console [
<span id="L1411" class="LineNr">1411 </span> <span class="Conceal">¦</span> type <span class="Constant">[abc]</span>
<span id="L1412" class="LineNr">1412 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 1</span>,<span class="Constant"> 1</span>
<span id="L1413" class="LineNr">1413 </span> <span class="Conceal">¦</span> type <span class="Constant">[d]</span>
<span id="L1414" class="LineNr">1414 </span> ]
<span id="L1415" class="LineNr">1415 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1416" class="LineNr">1416 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1417" class="LineNr">1417 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1418" class="LineNr">1418 </span> screen-should-contain [
<span id="L1419" class="LineNr">1419 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1420" class="LineNr">1420 </span> <span class="Conceal">¦</span><span class="Constant"> .adbc .</span>
<span id="L1421" class="LineNr">1421 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1422" class="LineNr">1422 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1423" class="LineNr">1423 </span> ]
<span id="L1424" class="LineNr">1424 </span> memory-should-contain [
<span id="L1425" class="LineNr">1425 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1426" class="LineNr">1426 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1427" class="LineNr">1427 </span> ]
<span id="L1428" class="LineNr">1428 </span> <span class="Comment"># undo</span>
<span id="L1429" class="LineNr">1429 </span> assume-console [
<span id="L1430" class="LineNr">1430 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1431" class="LineNr">1431 </span> ]
<span id="L1432" class="LineNr">1432 </span> run [
<span id="L1433" class="LineNr">1433 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1434" class="LineNr">1434 </span> <span class="Conceal">¦</span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1435" class="LineNr">1435 </span> <span class="Conceal">¦</span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1436" class="LineNr">1436 </span> ]
<span id="L1437" class="LineNr">1437 </span> <span class="Comment"># last letter typed is deleted</span>
<span id="L1438" class="LineNr">1438 </span> screen-should-contain [
<span id="L1439" class="LineNr">1439 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1440" class="LineNr">1440 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1441" class="LineNr">1441 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1442" class="LineNr">1442 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1443" class="LineNr">1443 </span> ]
<span id="L1444" class="LineNr">1444 </span> memory-should-contain [
<span id="L1445" class="LineNr">1445 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1446" class="LineNr">1446 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1447" class="LineNr">1447 </span> ]
<span id="L1448" class="LineNr">1448 </span> <span class="Comment"># undo again</span>
<span id="L1449" class="LineNr">1449 </span> assume-console [
<span id="L1450" class="LineNr">1450 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1451" class="LineNr">1451 </span> ]
<span id="L1452" class="LineNr">1452 </span> run [
<span id="L1453" class="LineNr">1453 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1454" class="LineNr">1454 </span> <span class="Conceal">¦</span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1455" class="LineNr">1455 </span> <span class="Conceal">¦</span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1456" class="LineNr">1456 </span> ]
<span id="L1457" class="LineNr">1457 </span> <span class="Comment"># no change to screen; cursor moves</span>
<span id="L1458" class="LineNr">1458 </span> screen-should-contain [
<span id="L1459" class="LineNr">1459 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1460" class="LineNr">1460 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1461" class="LineNr">1461 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1462" class="LineNr">1462 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1463" class="LineNr">1463 </span> ]
<span id="L1464" class="LineNr">1464 </span> memory-should-contain [
<span id="L1465" class="LineNr">1465 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1466" class="LineNr">1466 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L1467" class="LineNr">1467 </span> ]
<span id="L1468" class="LineNr">1468 </span> <span class="Comment"># undo again</span>
<span id="L1469" class="LineNr">1469 </span> assume-console [
<span id="L1470" class="LineNr">1470 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1471" class="LineNr">1471 </span> ]
<span id="L1472" class="LineNr">1472 </span> run [
<span id="L1473" class="LineNr">1473 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1474" class="LineNr">1474 </span> <span class="Conceal">¦</span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1475" class="LineNr">1475 </span> <span class="Conceal">¦</span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1476" class="LineNr">1476 </span> ]
<span id="L1477" class="LineNr">1477 </span> <span class="Comment"># screen empty</span>
<span id="L1478" class="LineNr">1478 </span> screen-should-contain [
<span id="L1479" class="LineNr">1479 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1480" class="LineNr">1480 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1481" class="LineNr">1481 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1482" class="LineNr">1482 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1483" class="LineNr">1483 </span> ]
<span id="L1484" class="LineNr">1484 </span> memory-should-contain [
<span id="L1485" class="LineNr">1485 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1486" class="LineNr">1486 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 0</span>
<span id="L1487" class="LineNr">1487 </span> ]
<span id="L1488" class="LineNr">1488 </span> <span class="Comment"># redo</span>
<span id="L1489" class="LineNr">1489 </span> assume-console [
<span id="L1490" class="LineNr">1490 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1491" class="LineNr">1491 </span> ]
<span id="L1492" class="LineNr">1492 </span> run [
<span id="L1493" class="LineNr">1493 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1494" class="LineNr">1494 </span> <span class="Conceal">¦</span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1495" class="LineNr">1495 </span> <span class="Conceal">¦</span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1496" class="LineNr">1496 </span> ]
<span id="L1497" class="LineNr">1497 </span> <span class="Comment"># first insert</span>
<span id="L1498" class="LineNr">1498 </span> screen-should-contain [
<span id="L1499" class="LineNr">1499 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1500" class="LineNr">1500 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1501" class="LineNr">1501 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1502" class="LineNr">1502 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1503" class="LineNr">1503 </span> ]
<span id="L1504" class="LineNr">1504 </span> memory-should-contain [
<span id="L1505" class="LineNr">1505 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1506" class="LineNr">1506 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L1507" class="LineNr">1507 </span> ]
<span id="L1508" class="LineNr">1508 </span> <span class="Comment"># redo again</span>
<span id="L1509" class="LineNr">1509 </span> assume-console [
<span id="L1510" class="LineNr">1510 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1511" class="LineNr">1511 </span> ]
<span id="L1512" class="LineNr">1512 </span> run [
<span id="L1513" class="LineNr">1513 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1514" class="LineNr">1514 </span> <span class="Conceal">¦</span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1515" class="LineNr">1515 </span> <span class="Conceal">¦</span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1516" class="LineNr">1516 </span> ]
<span id="L1517" class="LineNr">1517 </span> <span class="Comment"># cursor moves</span>
<span id="L1518" class="LineNr">1518 </span> screen-should-contain [
<span id="L1519" class="LineNr">1519 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1520" class="LineNr">1520 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1521" class="LineNr">1521 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1522" class="LineNr">1522 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1523" class="LineNr">1523 </span> ]
<span id="L1524" class="LineNr">1524 </span> <span class="Comment"># cursor moves</span>
<span id="L1525" class="LineNr">1525 </span> memory-should-contain [
<span id="L1526" class="LineNr">1526 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1527" class="LineNr">1527 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1528" class="LineNr">1528 </span> ]
<span id="L1529" class="LineNr">1529 </span> <span class="Comment"># redo again</span>
<span id="L1530" class="LineNr">1530 </span> assume-console [
<span id="L1531" class="LineNr">1531 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1532" class="LineNr">1532 </span> ]
<span id="L1533" class="LineNr">1533 </span> run [
<span id="L1534" class="LineNr">1534 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1535" class="LineNr">1535 </span> <span class="Conceal">¦</span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1536" class="LineNr">1536 </span> <span class="Conceal">¦</span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1537" class="LineNr">1537 </span> ]
<span id="L1538" class="LineNr">1538 </span> <span class="Comment"># second insert</span>
<span id="L1539" class="LineNr">1539 </span> screen-should-contain [
<span id="L1540" class="LineNr">1540 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1541" class="LineNr">1541 </span> <span class="Conceal">¦</span><span class="Constant"> .adbc .</span>
<span id="L1542" class="LineNr">1542 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1543" class="LineNr">1543 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1544" class="LineNr">1544 </span> ]
<span id="L1545" class="LineNr">1545 </span> memory-should-contain [
<span id="L1546" class="LineNr">1546 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1547" class="LineNr">1547 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1548" class="LineNr">1548 </span> ]
<span id="L1549" class="LineNr">1549 </span>]
<span id="L1550" class="LineNr">1550 </span>
<span id="L1551" class="LineNr">1551 </span><span class="Comment"># undo backspace</span>
<span id="L1552" class="LineNr">1552 </span>
<span id="L1553" class="LineNr">1553 </span><span class="muScenario">scenario</span> editor-can-undo-and-redo-backspace [
<span id="L1554" class="LineNr">1554 </span> <span class="Constant">local-scope</span>
<span id="L1555" class="LineNr">1555 </span> <span class="Comment"># create an editor</span>
<span id="L1556" class="LineNr">1556 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1557" class="LineNr">1557 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1558" class="LineNr">1558 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1559" class="LineNr">1559 </span> <span class="Comment"># insert some text and hit backspace</span>
<span id="L1560" class="LineNr">1560 </span> assume-console [
<span id="L1561" class="LineNr">1561 </span> <span class="Conceal">¦</span> type <span class="Constant">[abc]</span>
<span id="L1562" class="LineNr">1562 </span> <span class="Conceal">¦</span> press backspace
<span id="L1563" class="LineNr">1563 </span> <span class="Conceal">¦</span> press backspace
<span id="L1564" class="LineNr">1564 </span> ]
<span id="L1565" class="LineNr">1565 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1566" class="LineNr">1566 </span> screen-should-contain [
<span id="L1567" class="LineNr">1567 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1568" class="LineNr">1568 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L1569" class="LineNr">1569 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1570" class="LineNr">1570 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1571" class="LineNr">1571 </span> ]
<span id="L1572" class="LineNr">1572 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1573" class="LineNr">1573 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1574" class="LineNr">1574 </span> memory-should-contain [
<span id="L1575" class="LineNr">1575 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1576" class="LineNr">1576 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1577" class="LineNr">1577 </span> ]
<span id="L1578" class="LineNr">1578 </span> <span class="Comment"># undo</span>
<span id="L1579" class="LineNr">1579 </span> assume-console [
<span id="L1580" class="LineNr">1580 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1581" class="LineNr">1581 </span> ]
<span id="L1582" class="LineNr">1582 </span> run [
<span id="L1583" class="LineNr">1583 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1584" class="LineNr">1584 </span> ]
<span id="L1585" class="LineNr">1585 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1586" class="LineNr">1586 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1587" class="LineNr">1587 </span> memory-should-contain [
<span id="L1588" class="LineNr">1588 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1589" class="LineNr">1589 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 3</span>
<span id="L1590" class="LineNr">1590 </span> ]
<span id="L1591" class="LineNr">1591 </span> screen-should-contain [
<span id="L1592" class="LineNr">1592 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1593" class="LineNr">1593 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1594" class="LineNr">1594 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1595" class="LineNr">1595 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1596" class="LineNr">1596 </span> ]
<span id="L1597" class="LineNr">1597 </span> <span class="Comment"># redo</span>
<span id="L1598" class="LineNr">1598 </span> assume-console [
<span id="L1599" class="LineNr">1599 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1600" class="LineNr">1600 </span> ]
<span id="L1601" class="LineNr">1601 </span> run [
<span id="L1602" class="LineNr">1602 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1603" class="LineNr">1603 </span> ]
<span id="L1604" class="LineNr">1604 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1605" class="LineNr">1605 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1606" class="LineNr">1606 </span> memory-should-contain [
<span id="L1607" class="LineNr">1607 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1608" class="LineNr">1608 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1609" class="LineNr">1609 </span> ]
<span id="L1610" class="LineNr">1610 </span> screen-should-contain [
<span id="L1611" class="LineNr">1611 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1612" class="LineNr">1612 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L1613" class="LineNr">1613 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1614" class="LineNr">1614 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1615" class="LineNr">1615 </span> ]
<span id="L1616" class="LineNr">1616 </span>]
<span id="L1617" class="LineNr">1617 </span>
<span id="L1618" class="LineNr">1618 </span><span class="Comment"># save operation to undo</span>
<span id="L1619" class="LineNr">1619 </span><span class="muRecipe">after</span> <span class="Constant"><a href='003-shortcuts.mu.html#L72'><backspace-character-begin></a></span> [
<span id="L1620" class="LineNr">1620 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L1621" class="LineNr">1621 </span>]
<span id="L1622" class="LineNr">1622 </span><span class="muRecipe">before</span> <span class="Constant"><a href='003-shortcuts.mu.html#L74'><backspace-character-end></a></span> [
<span id="L1623" class="LineNr">1623 </span> <span class="Delimiter">{</span>
<span id="L1624" class="LineNr">1624 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> backspaced-cell <span class="Comment"># backspace failed; don't add an undo operation</span>
<span id="L1625" class="LineNr">1625 </span> <span class="Conceal">¦</span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L1626" class="LineNr">1626 </span> <span class="Conceal">¦</span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L1627" class="LineNr">1627 </span> <span class="Conceal">¦</span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L1628" class="LineNr">1628 </span> <span class="Conceal">¦</span> before-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L1629" class="LineNr">1629 </span> <span class="Conceal">¦</span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L1630" class="LineNr">1630 </span> <span class="Conceal">¦</span> <span class="Delimiter">{</span>
<span id="L1631" class="LineNr">1631 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Comment"># if previous operation was an insert, coalesce this operation with it</span>
<span id="L1632" class="LineNr">1632 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo
<span id="L1633" class="LineNr">1633 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> first undo
<span id="L1634" class="LineNr">1634 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion:<a href='012-editor-undo.mu.html#L43'>delete-operation</a>, is-delete?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">delete:variant</span>
<span id="L1635" class="LineNr">1635 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-delete?
<span id="L1636" class="LineNr">1636 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> previous-coalesce-tag:num <span class="Special"><-</span> get deletion, <span class="Constant">tag:offset</span>
<span id="L1637" class="LineNr">1637 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> coalesce?:bool <span class="Special"><-</span> equal previous-coalesce-tag, <span class="Constant">1/coalesce-backspace</span>
<span id="L1638" class="LineNr">1638 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> coalesce?
<span id="L1639" class="LineNr">1639 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">delete-from:offset</span>, before-cursor
<span id="L1640" class="LineNr">1640 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> backspaced-so-far:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">deleted-text:offset</span>
<span id="L1641" class="LineNr">1641 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <a href='../065duplex_list.mu.html#L529'>splice</a> backspaced-cell, backspaced-so-far
<span id="L1642" class="LineNr">1642 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">deleted-text:offset</span>, backspaced-cell
<span id="L1643" class="LineNr">1643 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">after-row:offset</span>, cursor-row
<span id="L1644" class="LineNr">1644 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">after-column:offset</span>, cursor-column
<span id="L1645" class="LineNr">1645 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">after-top-of-screen:offset</span>, top-after
<span id="L1646" class="LineNr">1646 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">2/delete-operation</span>, deletion
<span id="L1647" class="LineNr">1647 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break</span> <span class="Constant">+done-adding-backspace-operation</span>
<span id="L1648" class="LineNr">1648 </span> <span class="Conceal">¦</span> <span class="Delimiter">}</span>
<span id="L1649" class="LineNr">1649 </span> <span class="Conceal">¦</span> <span class="Comment"># if not, create a new operation</span>
<span id="L1650" class="LineNr">1650 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L1651" class="LineNr">1651 </span> <span class="Conceal">¦</span> deleted-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L1652" class="LineNr">1652 </span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">2/delete-operation</span>, save-row/before, save-column/before, top-before, cursor-row/after, cursor-column/after, top-after, backspaced-cell/deleted, before-cursor/delete-from, deleted-until, <span class="Constant">1/coalesce-backspace</span>
<span id="L1653" class="LineNr">1653 </span> <span class="Conceal">¦</span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L1654" class="LineNr">1654 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> +done-adding-backspace-operation</span>
<span id="L1655" class="LineNr">1655 </span> <span class="Delimiter">}</span>
<span id="L1656" class="LineNr">1656 </span>]
<span id="L1657" class="LineNr">1657 </span>
<span id="L1658" class="LineNr">1658 </span><span class="muRecipe">after</span> <span class="Constant"><a href='012-editor-undo.mu.html#L78'><handle-undo></a></span> [
<span id="L1659" class="LineNr">1659 </span> <span class="Delimiter">{</span>
<span id="L1660" class="LineNr">1660 </span> <span class="Conceal">¦</span> deletion:<a href='012-editor-undo.mu.html#L43'>delete-operation</a>, is-delete?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">delete:variant</span>
<span id="L1661" class="LineNr">1661 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-delete?
<span id="L1662" class="LineNr">1662 </span> <span class="Conceal">¦</span> anchor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">delete-from:offset</span>
<span id="L1663" class="LineNr">1663 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> anchor
<span id="L1664" class="LineNr">1664 </span> <span class="Conceal">¦</span> deleted:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">deleted-text:offset</span>
<span id="L1665" class="LineNr">1665 </span> <span class="Conceal">¦</span> old-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L576'>last</a> deleted
<span id="L1666" class="LineNr">1666 </span> <span class="Conceal">¦</span> <a href='../065duplex_list.mu.html#L529'>splice</a> anchor, deleted
<span id="L1667" class="LineNr">1667 </span> <span class="Conceal">¦</span> <span class="Comment"># assert cursor-row/cursor-column/top-of-screen match after-row/after-column/after-top-of-screen</span>
<span id="L1668" class="LineNr">1668 </span> <span class="Conceal">¦</span> before-cursor <span class="Special"><-</span> copy old-cursor
<span id="L1669" class="LineNr">1669 </span> <span class="Conceal">¦</span> cursor-row <span class="Special"><-</span> get deletion, <span class="Constant">before-row:offset</span>
<span id="L1670" class="LineNr">1670 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-row:offset</span>, cursor-row
<span id="L1671" class="LineNr">1671 </span> <span class="Conceal">¦</span> cursor-column <span class="Special"><-</span> get deletion, <span class="Constant">before-column:offset</span>
<span id="L1672" class="LineNr">1672 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-column:offset</span>, cursor-column
<span id="L1673" class="LineNr">1673 </span> <span class="Conceal">¦</span> top:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">before-top-of-screen:offset</span>
<span id="L1674" class="LineNr">1674 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">top-of-screen:offset</span>, top
<span id="L1675" class="LineNr">1675 </span> <span class="Delimiter">}</span>
<span id="L1676" class="LineNr">1676 </span>]
<span id="L1677" class="LineNr">1677 </span>
<span id="L1678" class="LineNr">1678 </span><span class="muRecipe">after</span> <span class="Constant"><a href='012-editor-undo.mu.html#L96'><handle-redo></a></span> [
<span id="L1679" class="LineNr">1679 </span> <span class="Delimiter">{</span>
<span id="L1680" class="LineNr">1680 </span> <span class="Conceal">¦</span> deletion:<a href='012-editor-undo.mu.html#L43'>delete-operation</a>, is-delete?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">delete:variant</span>
<span id="L1681" class="LineNr">1681 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-delete?
<span id="L1682" class="LineNr">1682 </span> <span class="Conceal">¦</span> start:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">delete-from:offset</span>
<span id="L1683" class="LineNr">1683 </span> <span class="Conceal">¦</span> end:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">delete-until:offset</span>
<span id="L1684" class="LineNr">1684 </span> <span class="Conceal">¦</span> data:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">data:offset</span>
<span id="L1685" class="LineNr">1685 </span> <span class="Conceal">¦</span> <a href='../065duplex_list.mu.html#L389'>remove-between</a> start, end
<span id="L1686" class="LineNr">1686 </span> <span class="Conceal">¦</span> <span class="Comment"># assert cursor-row/cursor-column/top-of-screen match after-row/after-column/after-top-of-screen</span>
<span id="L1687" class="LineNr">1687 </span> <span class="Conceal">¦</span> cursor-row <span class="Special"><-</span> get deletion, <span class="Constant">after-row:offset</span>
<span id="L1688" class="LineNr">1688 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-row:offset</span>, cursor-row
<span id="L1689" class="LineNr">1689 </span> <span class="Conceal">¦</span> cursor-column <span class="Special"><-</span> get deletion, <span class="Constant">after-column:offset</span>
<span id="L1690" class="LineNr">1690 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">cursor-column:offset</span>, cursor-column
<span id="L1691" class="LineNr">1691 </span> <span class="Conceal">¦</span> top:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">before-top-of-screen:offset</span>
<span id="L1692" class="LineNr">1692 </span> <span class="Conceal">¦</span> *editor <span class="Special"><-</span> put *editor, <span class="Constant">top-of-screen:offset</span>, top
<span id="L1693" class="LineNr">1693 </span> <span class="Delimiter">}</span>
<span id="L1694" class="LineNr">1694 </span>]
<span id="L1695" class="LineNr">1695 </span>
<span id="L1696" class="LineNr">1696 </span><span class="Comment"># undo delete</span>
<span id="L1697" class="LineNr">1697 </span>
<span id="L1698" class="LineNr">1698 </span><span class="muScenario">scenario</span> editor-can-undo-and-redo-delete [
<span id="L1699" class="LineNr">1699 </span> <span class="Constant">local-scope</span>
<span id="L1700" class="LineNr">1700 </span> <span class="Comment"># create an editor</span>
<span id="L1701" class="LineNr">1701 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1702" class="LineNr">1702 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1703" class="LineNr">1703 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1704" class="LineNr">1704 </span> <span class="Comment"># insert some text and hit delete and backspace a few times</span>
<span id="L1705" class="LineNr">1705 </span> assume-console [
<span id="L1706" class="LineNr">1706 </span> <span class="Conceal">¦</span> type <span class="Constant">[abcdef]</span>
<span id="L1707" class="LineNr">1707 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 1</span>,<span class="Constant"> 2</span>
<span id="L1708" class="LineNr">1708 </span> <span class="Conceal">¦</span> press delete
<span id="L1709" class="LineNr">1709 </span> <span class="Conceal">¦</span> press backspace
<span id="L1710" class="LineNr">1710 </span> <span class="Conceal">¦</span> press delete
<span id="L1711" class="LineNr">1711 </span> <span class="Conceal">¦</span> press delete
<span id="L1712" class="LineNr">1712 </span> ]
<span id="L1713" class="LineNr">1713 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1714" class="LineNr">1714 </span> screen-should-contain [
<span id="L1715" class="LineNr">1715 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1716" class="LineNr">1716 </span> <span class="Conceal">¦</span><span class="Constant"> .af .</span>
<span id="L1717" class="LineNr">1717 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1718" class="LineNr">1718 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1719" class="LineNr">1719 </span> ]
<span id="L1720" class="LineNr">1720 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1721" class="LineNr">1721 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1722" class="LineNr">1722 </span> memory-should-contain [
<span id="L1723" class="LineNr">1723 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1724" class="LineNr">1724 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1725" class="LineNr">1725 </span> ]
<span id="L1726" class="LineNr">1726 </span> <span class="Comment"># undo deletes</span>
<span id="L1727" class="LineNr">1727 </span> assume-console [
<span id="L1728" class="LineNr">1728 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1729" class="LineNr">1729 </span> ]
<span id="L1730" class="LineNr">1730 </span> run [
<span id="L1731" class="LineNr">1731 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1732" class="LineNr">1732 </span> ]
<span id="L1733" class="LineNr">1733 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1734" class="LineNr">1734 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1735" class="LineNr">1735 </span> memory-should-contain [
<span id="L1736" class="LineNr">1736 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1737" class="LineNr">1737 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1738" class="LineNr">1738 </span> ]
<span id="L1739" class="LineNr">1739 </span> screen-should-contain [
<span id="L1740" class="LineNr">1740 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1741" class="LineNr">1741 </span> <span class="Conceal">¦</span><span class="Constant"> .adef .</span>
<span id="L1742" class="LineNr">1742 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1743" class="LineNr">1743 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1744" class="LineNr">1744 </span> ]
<span id="L1745" class="LineNr">1745 </span> <span class="Comment"># undo backspace</span>
<span id="L1746" class="LineNr">1746 </span> assume-console [
<span id="L1747" class="LineNr">1747 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1748" class="LineNr">1748 </span> ]
<span id="L1749" class="LineNr">1749 </span> run [
<span id="L1750" class="LineNr">1750 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1751" class="LineNr">1751 </span> ]
<span id="L1752" class="LineNr">1752 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1753" class="LineNr">1753 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1754" class="LineNr">1754 </span> memory-should-contain [
<span id="L1755" class="LineNr">1755 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1756" class="LineNr">1756 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1757" class="LineNr">1757 </span> ]
<span id="L1758" class="LineNr">1758 </span> screen-should-contain [
<span id="L1759" class="LineNr">1759 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1760" class="LineNr">1760 </span> <span class="Conceal">¦</span><span class="Constant"> .abdef .</span>
<span id="L1761" class="LineNr">1761 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1762" class="LineNr">1762 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1763" class="LineNr">1763 </span> ]
<span id="L1764" class="LineNr">1764 </span> <span class="Comment"># undo first delete</span>
<span id="L1765" class="LineNr">1765 </span> assume-console [
<span id="L1766" class="LineNr">1766 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1767" class="LineNr">1767 </span> ]
<span id="L1768" class="LineNr">1768 </span> run [
<span id="L1769" class="LineNr">1769 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1770" class="LineNr">1770 </span> ]
<span id="L1771" class="LineNr">1771 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1772" class="LineNr">1772 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1773" class="LineNr">1773 </span> memory-should-contain [
<span id="L1774" class="LineNr">1774 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1775" class="LineNr">1775 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1776" class="LineNr">1776 </span> ]
<span id="L1777" class="LineNr">1777 </span> screen-should-contain [
<span id="L1778" class="LineNr">1778 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1779" class="LineNr">1779 </span> <span class="Conceal">¦</span><span class="Constant"> .abcdef .</span>
<span id="L1780" class="LineNr">1780 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1781" class="LineNr">1781 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1782" class="LineNr">1782 </span> ]
<span id="L1783" class="LineNr">1783 </span> <span class="Comment"># redo first delete</span>
<span id="L1784" class="LineNr">1784 </span> assume-console [
<span id="L1785" class="LineNr">1785 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1786" class="LineNr">1786 </span> ]
<span id="L1787" class="LineNr">1787 </span> run [
<span id="L1788" class="LineNr">1788 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1789" class="LineNr">1789 </span> ]
<span id="L1790" class="LineNr">1790 </span> <span class="Comment"># first line inserted</span>
<span id="L1791" class="LineNr">1791 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1792" class="LineNr">1792 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1793" class="LineNr">1793 </span> memory-should-contain [
<span id="L1794" class="LineNr">1794 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1795" class="LineNr">1795 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L1796" class="LineNr">1796 </span> ]
<span id="L1797" class="LineNr">1797 </span> screen-should-contain [
<span id="L1798" class="LineNr">1798 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1799" class="LineNr">1799 </span> <span class="Conceal">¦</span><span class="Constant"> .abdef .</span>
<span id="L1800" class="LineNr">1800 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1801" class="LineNr">1801 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1802" class="LineNr">1802 </span> ]
<span id="L1803" class="LineNr">1803 </span> <span class="Comment"># redo backspace</span>
<span id="L1804" class="LineNr">1804 </span> assume-console [
<span id="L1805" class="LineNr">1805 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1806" class="LineNr">1806 </span> ]
<span id="L1807" class="LineNr">1807 </span> run [
<span id="L1808" class="LineNr">1808 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1809" class="LineNr">1809 </span> ]
<span id="L1810" class="LineNr">1810 </span> <span class="Comment"># first line inserted</span>
<span id="L1811" class="LineNr">1811 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1812" class="LineNr">1812 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1813" class="LineNr">1813 </span> memory-should-contain [
<span id="L1814" class="LineNr">1814 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1815" class="LineNr">1815 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1816" class="LineNr">1816 </span> ]
<span id="L1817" class="LineNr">1817 </span> screen-should-contain [
<span id="L1818" class="LineNr">1818 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1819" class="LineNr">1819 </span> <span class="Conceal">¦</span><span class="Constant"> .adef .</span>
<span id="L1820" class="LineNr">1820 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1821" class="LineNr">1821 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1822" class="LineNr">1822 </span> ]
<span id="L1823" class="LineNr">1823 </span> <span class="Comment"># redo deletes</span>
<span id="L1824" class="LineNr">1824 </span> assume-console [
<span id="L1825" class="LineNr">1825 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1826" class="LineNr">1826 </span> ]
<span id="L1827" class="LineNr">1827 </span> run [
<span id="L1828" class="LineNr">1828 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1829" class="LineNr">1829 </span> ]
<span id="L1830" class="LineNr">1830 </span> <span class="Comment"># first line inserted</span>
<span id="L1831" class="LineNr">1831 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1832" class="LineNr">1832 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1833" class="LineNr">1833 </span> memory-should-contain [
<span id="L1834" class="LineNr">1834 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1835" class="LineNr">1835 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1836" class="LineNr">1836 </span> ]
<span id="L1837" class="LineNr">1837 </span> screen-should-contain [
<span id="L1838" class="LineNr">1838 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1839" class="LineNr">1839 </span> <span class="Conceal">¦</span><span class="Constant"> .af .</span>
<span id="L1840" class="LineNr">1840 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1841" class="LineNr">1841 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1842" class="LineNr">1842 </span> ]
<span id="L1843" class="LineNr">1843 </span>]
<span id="L1844" class="LineNr">1844 </span>
<span id="L1845" class="LineNr">1845 </span><span class="muRecipe">after</span> <span class="Constant"><a href='003-shortcuts.mu.html#L339'><delete-character-begin></a></span> [
<span id="L1846" class="LineNr">1846 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L1847" class="LineNr">1847 </span>]
<span id="L1848" class="LineNr">1848 </span><span class="muRecipe">before</span> <span class="Constant"><a href='003-shortcuts.mu.html#L341'><delete-character-end></a></span> [
<span id="L1849" class="LineNr">1849 </span> <span class="Delimiter">{</span>
<span id="L1850" class="LineNr">1850 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> deleted-cell <span class="Comment"># delete failed; don't add an undo operation</span>
<span id="L1851" class="LineNr">1851 </span> <span class="Conceal">¦</span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L1852" class="LineNr">1852 </span> <span class="Conceal">¦</span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L1853" class="LineNr">1853 </span> <span class="Conceal">¦</span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-column:offset</span>
<span id="L1854" class="LineNr">1854 </span> <span class="Conceal">¦</span> before-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L1855" class="LineNr">1855 </span> <span class="Conceal">¦</span> undo:&:<a href='../064list.mu.html#L6'>list</a>:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> get *editor, <span class="Constant">undo:offset</span>
<span id="L1856" class="LineNr">1856 </span> <span class="Conceal">¦</span> <span class="Delimiter">{</span>
<span id="L1857" class="LineNr">1857 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Comment"># if previous operation was an insert, coalesce this operation with it</span>
<span id="L1858" class="LineNr">1858 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> undo
<span id="L1859" class="LineNr">1859 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> first undo
<span id="L1860" class="LineNr">1860 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion:<a href='012-editor-undo.mu.html#L43'>delete-operation</a>, is-delete?:bool <span class="Special"><-</span> maybe-convert *op, <span class="Constant">delete:variant</span>
<span id="L1861" class="LineNr">1861 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> is-delete?
<span id="L1862" class="LineNr">1862 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> previous-coalesce-tag:num <span class="Special"><-</span> get deletion, <span class="Constant">tag:offset</span>
<span id="L1863" class="LineNr">1863 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> coalesce?:bool <span class="Special"><-</span> equal previous-coalesce-tag, <span class="Constant">2/coalesce-delete</span>
<span id="L1864" class="LineNr">1864 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> coalesce?
<span id="L1865" class="LineNr">1865 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> delete-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L1866" class="LineNr">1866 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">delete-until:offset</span>, delete-until
<span id="L1867" class="LineNr">1867 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deleted-so-far:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get deletion, <span class="Constant">deleted-text:offset</span>
<span id="L1868" class="LineNr">1868 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deleted-so-far <span class="Special"><-</span> append deleted-so-far, deleted-cell
<span id="L1869" class="LineNr">1869 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">deleted-text:offset</span>, deleted-so-far
<span id="L1870" class="LineNr">1870 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">after-row:offset</span>, cursor-row
<span id="L1871" class="LineNr">1871 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">after-column:offset</span>, cursor-column
<span id="L1872" class="LineNr">1872 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> deletion <span class="Special"><-</span> put deletion, <span class="Constant">after-top-of-screen:offset</span>, top-after
<span id="L1873" class="LineNr">1873 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">2/delete-operation</span>, deletion
<span id="L1874" class="LineNr">1874 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break</span> <span class="Constant">+done-adding-delete-operation</span>
<span id="L1875" class="LineNr">1875 </span> <span class="Conceal">¦</span> <span class="Delimiter">}</span>
<span id="L1876" class="LineNr">1876 </span> <span class="Conceal">¦</span> <span class="Comment"># if not, create a new operation</span>
<span id="L1877" class="LineNr">1877 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L1878" class="LineNr">1878 </span> <span class="Conceal">¦</span> deleted-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L1879" class="LineNr">1879 </span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">2/delete-operation</span>, save-row/before, save-column/before, top-before, cursor-row/after, cursor-column/after, top-after, deleted-cell/deleted, before-cursor/delete-from, deleted-until, <span class="Constant">2/coalesce-delete</span>
<span id="L1880" class="LineNr">1880 </span> <span class="Conceal">¦</span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L1881" class="LineNr">1881 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> +done-adding-delete-operation</span>
<span id="L1882" class="LineNr">1882 </span> <span class="Delimiter">}</span>
<span id="L1883" class="LineNr">1883 </span>]
<span id="L1884" class="LineNr">1884 </span>
<span id="L1885" class="LineNr">1885 </span><span class="Comment"># undo ctrl-k</span>
<span id="L1886" class="LineNr">1886 </span>
<span id="L1887" class="LineNr">1887 </span><span class="muScenario">scenario</span> editor-can-undo-and-redo-ctrl-k [
<span id="L1888" class="LineNr">1888 </span> <span class="Constant">local-scope</span>
<span id="L1889" class="LineNr">1889 </span> <span class="Comment"># create an editor</span>
<span id="L1890" class="LineNr">1890 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1891" class="LineNr">1891 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1892" class="LineNr">1892 </span><span class="Constant">def]</span>
<span id="L1893" class="LineNr">1893 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1894" class="LineNr">1894 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1895" class="LineNr">1895 </span> <span class="Comment"># insert some text and hit delete and backspace a few times</span>
<span id="L1896" class="LineNr">1896 </span> assume-console [
<span id="L1897" class="LineNr">1897 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 1</span>,<span class="Constant"> 1</span>
<span id="L1898" class="LineNr">1898 </span> <span class="Conceal">¦</span> press ctrl-k
<span id="L1899" class="LineNr">1899 </span> ]
<span id="L1900" class="LineNr">1900 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1901" class="LineNr">1901 </span> screen-should-contain [
<span id="L1902" class="LineNr">1902 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1903" class="LineNr">1903 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L1904" class="LineNr">1904 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L1905" class="LineNr">1905 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1906" class="LineNr">1906 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1907" class="LineNr">1907 </span> ]
<span id="L1908" class="LineNr">1908 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1909" class="LineNr">1909 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1910" class="LineNr">1910 </span> memory-should-contain [
<span id="L1911" class="LineNr">1911 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1912" class="LineNr">1912 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1913" class="LineNr">1913 </span> ]
<span id="L1914" class="LineNr">1914 </span> <span class="Comment"># undo</span>
<span id="L1915" class="LineNr">1915 </span> assume-console [
<span id="L1916" class="LineNr">1916 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L1917" class="LineNr">1917 </span> ]
<span id="L1918" class="LineNr">1918 </span> run [
<span id="L1919" class="LineNr">1919 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1920" class="LineNr">1920 </span> ]
<span id="L1921" class="LineNr">1921 </span> screen-should-contain [
<span id="L1922" class="LineNr">1922 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1923" class="LineNr">1923 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L1924" class="LineNr">1924 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L1925" class="LineNr">1925 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1926" class="LineNr">1926 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1927" class="LineNr">1927 </span> ]
<span id="L1928" class="LineNr">1928 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1929" class="LineNr">1929 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1930" class="LineNr">1930 </span> memory-should-contain [
<span id="L1931" class="LineNr">1931 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1932" class="LineNr">1932 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1933" class="LineNr">1933 </span> ]
<span id="L1934" class="LineNr">1934 </span> <span class="Comment"># redo</span>
<span id="L1935" class="LineNr">1935 </span> assume-console [
<span id="L1936" class="LineNr">1936 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L1937" class="LineNr">1937 </span> ]
<span id="L1938" class="LineNr">1938 </span> run [
<span id="L1939" class="LineNr">1939 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1940" class="LineNr">1940 </span> ]
<span id="L1941" class="LineNr">1941 </span> <span class="Comment"># first line inserted</span>
<span id="L1942" class="LineNr">1942 </span> screen-should-contain [
<span id="L1943" class="LineNr">1943 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1944" class="LineNr">1944 </span> <span class="Conceal">¦</span><span class="Constant"> .a .</span>
<span id="L1945" class="LineNr">1945 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L1946" class="LineNr">1946 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1947" class="LineNr">1947 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1948" class="LineNr">1948 </span> ]
<span id="L1949" class="LineNr">1949 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L1950" class="LineNr">1950 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L1951" class="LineNr">1951 </span> memory-should-contain [
<span id="L1952" class="LineNr">1952 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1953" class="LineNr">1953 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L1954" class="LineNr">1954 </span> ]
<span id="L1955" class="LineNr">1955 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L1956" class="LineNr">1956 </span> assume-console [
<span id="L1957" class="LineNr">1957 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L1958" class="LineNr">1958 </span> ]
<span id="L1959" class="LineNr">1959 </span> run [
<span id="L1960" class="LineNr">1960 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L1961" class="LineNr">1961 </span> ]
<span id="L1962" class="LineNr">1962 </span> screen-should-contain [
<span id="L1963" class="LineNr">1963 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1964" class="LineNr">1964 </span> <span class="Conceal">¦</span><span class="Constant"> .a1 .</span>
<span id="L1965" class="LineNr">1965 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L1966" class="LineNr">1966 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L1967" class="LineNr">1967 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L1968" class="LineNr">1968 </span> ]
<span id="L1969" class="LineNr">1969 </span>]
<span id="L1970" class="LineNr">1970 </span>
<span id="L1971" class="LineNr">1971 </span><span class="muRecipe">after</span> <span class="Constant"><a href='003-shortcuts.mu.html#L1897'><delete-to-end-of-line-begin></a></span> [
<span id="L1972" class="LineNr">1972 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L1973" class="LineNr">1973 </span>]
<span id="L1974" class="LineNr">1974 </span><span class="muRecipe">before</span> <span class="Constant"><a href='003-shortcuts.mu.html#L1899'><delete-to-end-of-line-end></a></span> [
<span id="L1975" class="LineNr">1975 </span> <span class="Delimiter">{</span>
<span id="L1976" class="LineNr">1976 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> deleted-cells <span class="Comment"># delete failed; don't add an undo operation</span>
<span id="L1977" class="LineNr">1977 </span> <span class="Conceal">¦</span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L1978" class="LineNr">1978 </span> <span class="Conceal">¦</span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L1979" class="LineNr">1979 </span> <span class="Conceal">¦</span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-column:offset</span>
<span id="L1980" class="LineNr">1980 </span> <span class="Conceal">¦</span> deleted-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L1981" class="LineNr">1981 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L1982" class="LineNr">1982 </span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">2/delete-operation</span>, save-row/before, save-column/before, top-before, cursor-row/after, cursor-column/after, top-after, deleted-cells/deleted, before-cursor/delete-from, deleted-until, <span class="Constant">0/never-coalesce</span>
<span id="L1983" class="LineNr">1983 </span> <span class="Conceal">¦</span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L1984" class="LineNr">1984 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> +done-adding-delete-operation</span>
<span id="L1985" class="LineNr">1985 </span> <span class="Delimiter">}</span>
<span id="L1986" class="LineNr">1986 </span>]
<span id="L1987" class="LineNr">1987 </span>
<span id="L1988" class="LineNr">1988 </span><span class="Comment"># undo ctrl-u</span>
<span id="L1989" class="LineNr">1989 </span>
<span id="L1990" class="LineNr">1990 </span><span class="muScenario">scenario</span> editor-can-undo-and-redo-ctrl-u [
<span id="L1991" class="LineNr">1991 </span> <span class="Constant">local-scope</span>
<span id="L1992" class="LineNr">1992 </span> <span class="Comment"># create an editor</span>
<span id="L1993" class="LineNr">1993 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L1994" class="LineNr">1994 </span> contents:text <span class="Special"><-</span> new <span class="Constant">[abc</span>
<span id="L1995" class="LineNr">1995 </span><span class="Constant">def]</span>
<span id="L1996" class="LineNr">1996 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> contents, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L1997" class="LineNr">1997 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L1998" class="LineNr">1998 </span> <span class="Comment"># insert some text and hit delete and backspace a few times</span>
<span id="L1999" class="LineNr">1999 </span> assume-console [
<span id="L2000" class="LineNr">2000 </span> <span class="Conceal">¦</span> left-click<span class="Constant"> 1</span>,<span class="Constant"> 2</span>
<span id="L2001" class="LineNr">2001 </span> <span class="Conceal">¦</span> press ctrl-u
<span id="L2002" class="LineNr">2002 </span> ]
<span id="L2003" class="LineNr">2003 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L2004" class="LineNr">2004 </span> screen-should-contain [
<span id="L2005" class="LineNr">2005 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2006" class="LineNr">2006 </span> <span class="Conceal">¦</span><span class="Constant"> .c .</span>
<span id="L2007" class="LineNr">2007 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L2008" class="LineNr">2008 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L2009" class="LineNr">2009 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2010" class="LineNr">2010 </span> ]
<span id="L2011" class="LineNr">2011 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L2012" class="LineNr">2012 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L2013" class="LineNr">2013 </span> memory-should-contain [
<span id="L2014" class="LineNr">2014 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L2015" class="LineNr">2015 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 0</span>
<span id="L2016" class="LineNr">2016 </span> ]
<span id="L2017" class="LineNr">2017 </span> <span class="Comment"># undo</span>
<span id="L2018" class="LineNr">2018 </span> assume-console [
<span id="L2019" class="LineNr">2019 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L2020" class="LineNr">2020 </span> ]
<span id="L2021" class="LineNr">2021 </span> run [
<span id="L2022" class="LineNr">2022 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L2023" class="LineNr">2023 </span> ]
<span id="L2024" class="LineNr">2024 </span> screen-should-contain [
<span id="L2025" class="LineNr">2025 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2026" class="LineNr">2026 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L2027" class="LineNr">2027 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L2028" class="LineNr">2028 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L2029" class="LineNr">2029 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2030" class="LineNr">2030 </span> ]
<span id="L2031" class="LineNr">2031 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L2032" class="LineNr">2032 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L2033" class="LineNr">2033 </span> memory-should-contain [
<span id="L2034" class="LineNr">2034 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L2035" class="LineNr">2035 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 2</span>
<span id="L2036" class="LineNr">2036 </span> ]
<span id="L2037" class="LineNr">2037 </span> <span class="Comment"># redo</span>
<span id="L2038" class="LineNr">2038 </span> assume-console [
<span id="L2039" class="LineNr">2039 </span> <span class="Conceal">¦</span> press ctrl-y
<span id="L2040" class="LineNr">2040 </span> ]
<span id="L2041" class="LineNr">2041 </span> run [
<span id="L2042" class="LineNr">2042 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L2043" class="LineNr">2043 </span> ]
<span id="L2044" class="LineNr">2044 </span> <span class="Comment"># first line inserted</span>
<span id="L2045" class="LineNr">2045 </span> screen-should-contain [
<span id="L2046" class="LineNr">2046 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2047" class="LineNr">2047 </span> <span class="Conceal">¦</span><span class="Constant"> .c .</span>
<span id="L2048" class="LineNr">2048 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L2049" class="LineNr">2049 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L2050" class="LineNr">2050 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2051" class="LineNr">2051 </span> ]
<span id="L2052" class="LineNr">2052 </span> 3:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-row:offset</span>
<span id="L2053" class="LineNr">2053 </span> 4:num/<span class="Special">raw</span> <span class="Special"><-</span> get *e, <span class="Constant">cursor-column:offset</span>
<span id="L2054" class="LineNr">2054 </span> memory-should-contain [
<span id="L2055" class="LineNr">2055 </span> <span class="Conceal">¦</span><span class="Constant"> 3</span> <span class="Special"><-</span><span class="Constant"> 1</span>
<span id="L2056" class="LineNr">2056 </span> <span class="Conceal">¦</span><span class="Constant"> 4</span> <span class="Special"><-</span><span class="Constant"> 0</span>
<span id="L2057" class="LineNr">2057 </span> ]
<span id="L2058" class="LineNr">2058 </span> <span class="Comment"># cursor should be in the right place</span>
<span id="L2059" class="LineNr">2059 </span> assume-console [
<span id="L2060" class="LineNr">2060 </span> <span class="Conceal">¦</span> type <span class="Constant">[1]</span>
<span id="L2061" class="LineNr">2061 </span> ]
<span id="L2062" class="LineNr">2062 </span> run [
<span id="L2063" class="LineNr">2063 </span> <span class="Conceal">¦</span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L2064" class="LineNr">2064 </span> ]
<span id="L2065" class="LineNr">2065 </span> screen-should-contain [
<span id="L2066" class="LineNr">2066 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2067" class="LineNr">2067 </span> <span class="Conceal">¦</span><span class="Constant"> .1c .</span>
<span id="L2068" class="LineNr">2068 </span> <span class="Conceal">¦</span><span class="Constant"> .def .</span>
<span id="L2069" class="LineNr">2069 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L2070" class="LineNr">2070 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2071" class="LineNr">2071 </span> ]
<span id="L2072" class="LineNr">2072 </span>]
<span id="L2073" class="LineNr">2073 </span>
<span id="L2074" class="LineNr">2074 </span><span class="muRecipe">after</span> <span class="Constant"><a href='003-shortcuts.mu.html#L1653'><delete-to-start-of-line-begin></a></span> [
<span id="L2075" class="LineNr">2075 </span> top-before:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L2076" class="LineNr">2076 </span>]
<span id="L2077" class="LineNr">2077 </span><span class="muRecipe">before</span> <span class="Constant"><a href='003-shortcuts.mu.html#L1655'><delete-to-start-of-line-end></a></span> [
<span id="L2078" class="LineNr">2078 </span> <span class="Delimiter">{</span>
<span id="L2079" class="LineNr">2079 </span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> deleted-cells <span class="Comment"># delete failed; don't add an undo operation</span>
<span id="L2080" class="LineNr">2080 </span> <span class="Conceal">¦</span> top-after:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">top-of-screen:offset</span>
<span id="L2081" class="LineNr">2081 </span> <span class="Conceal">¦</span> op:&:<a href='012-editor-undo.mu.html#L5'>operation</a> <span class="Special"><-</span> new <span class="Constant"><a href='012-editor-undo.mu.html#L5'>operation</a>:type</span>
<span id="L2082" class="LineNr">2082 </span> <span class="Conceal">¦</span> before-cursor:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> get *editor, <span class="Constant">before-cursor:offset</span>
<span id="L2083" class="LineNr">2083 </span> <span class="Conceal">¦</span> deleted-until:&:<a href='../065duplex_list.mu.html#L3'>duplex-list</a>:char <span class="Special"><-</span> <a href='../065duplex_list.mu.html#L29'>next</a> before-cursor
<span id="L2084" class="LineNr">2084 </span> <span class="Conceal">¦</span> cursor-row:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-row:offset</span>
<span id="L2085" class="LineNr">2085 </span> <span class="Conceal">¦</span> cursor-column:num <span class="Special"><-</span> get *editor, <span class="Constant">cursor-column:offset</span>
<span id="L2086" class="LineNr">2086 </span> <span class="Conceal">¦</span> *op <span class="Special"><-</span> merge <span class="Constant">2/delete-operation</span>, save-row/before, save-column/before, top-before, cursor-row/after, cursor-column/after, top-after, deleted-cells/deleted, before-cursor/delete-from, deleted-until, <span class="Constant">0/never-coalesce</span>
<span id="L2087" class="LineNr">2087 </span> <span class="Conceal">¦</span> editor <span class="Special"><-</span> <a href='012-editor-undo.mu.html#L202'>add-operation</a> editor, op
<span id="L2088" class="LineNr">2088 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> +done-adding-delete-operation</span>
<span id="L2089" class="LineNr">2089 </span> <span class="Delimiter">}</span>
<span id="L2090" class="LineNr">2090 </span>]
<span id="L2091" class="LineNr">2091 </span>
<span id="L2092" class="LineNr">2092 </span><span class="muScenario">scenario</span> editor-can-undo-and-redo-ctrl-u-2 [
<span id="L2093" class="LineNr">2093 </span> <span class="Constant">local-scope</span>
<span id="L2094" class="LineNr">2094 </span> <span class="Comment"># create an editor</span>
<span id="L2095" class="LineNr">2095 </span> assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
<span id="L2096" class="LineNr">2096 </span> e:&:editor <span class="Special"><-</span> <a href='001-editor.mu.html#L51'>new-editor</a> <span class="Constant">[]</span>, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
<span id="L2097" class="LineNr">2097 </span> <a href='002-typing.mu.html#L265'>editor-render</a> <a href='../081print.mu.html#L4'>screen</a>, e
<span id="L2098" class="LineNr">2098 </span> <span class="Comment"># insert some text and hit delete and backspace a few times</span>
<span id="L2099" class="LineNr">2099 </span> assume-console [
<span id="L2100" class="LineNr">2100 </span> <span class="Conceal">¦</span> type <span class="Constant">[abc]</span>
<span id="L2101" class="LineNr">2101 </span> <span class="Conceal">¦</span> press ctrl-u
<span id="L2102" class="LineNr">2102 </span> <span class="Conceal">¦</span> press ctrl-z
<span id="L2103" class="LineNr">2103 </span> ]
<span id="L2104" class="LineNr">2104 </span> <a href='002-typing.mu.html#L16'>editor-event-loop</a> <a href='../081print.mu.html#L4'>screen</a>, <a href='../084console.mu.html#L23'>console</a>, e
<span id="L2105" class="LineNr">2105 </span> screen-should-contain [
<span id="L2106" class="LineNr">2106 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2107" class="LineNr">2107 </span> <span class="Conceal">¦</span><span class="Constant"> .abc .</span>
<span id="L2108" class="LineNr">2108 </span><span class="Constant"> </span><span class="Conceal">¦</span><span class="Constant"> .╌╌╌╌╌╌╌╌╌╌.</span>
<span id="L2109" class="LineNr">2109 </span> <span class="Conceal">¦</span><span class="Constant"> . .</span>
<span id="L2110" class="LineNr">2110 </span> ]
<span id="L2111" class="LineNr">2111 </span>]
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->