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<title>Mu - 081print.mu</title>
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* { font-size: 12pt; font-size: 1em; }
.muRecipe { color: #ff8700; }
.muData { color: #ffff00; }
.muScenario { color: #00af00; }
.Delimiter { color: #800080; }
.Comment { color: #9090ff; }
.Constant { color: #00a0a0; }
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<pre id='vimCodeElement'>
<span class="Comment"># Wrappers around print primitives that take a 'screen' object and are thus</span>
<span class="Comment"># easier to test.</span>

<span class="muData">container</span> screen [
  num-rows:number
  num-columns:number
  cursor-row:number
  cursor-column:number
  data:address:array:screen-cell
]

<span class="muData">container</span> screen-cell [
  contents:character
  color:number
]

<span class="muRecipe">def</span> new-fake-screen w:number, h:number<span class="muRecipe"> -&gt; </span>result:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  result<span class="Special"> &lt;- </span>new <span class="Constant">screen:type</span>
  bufsize:number<span class="Special"> &lt;- </span>multiply w, h
  data:address:array:screen-cell<span class="Special"> &lt;- </span>new <span class="Constant">screen-cell:type</span>, bufsize
  *result<span class="Special"> &lt;- </span>merge h/num-rows, w/num-columns, <span class="Constant">0/cursor-row</span>, <span class="Constant">0/cursor-column</span>, data
  result<span class="Special"> &lt;- </span>clear-screen result
]

<span class="muRecipe">def</span> clear-screen screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="Comment"># clear fake screen</span>
    buf:address:array:screen-cell<span class="Special"> &lt;- </span>get *screen, <span class="Constant">data:offset</span>
    max:number<span class="Special"> &lt;- </span>length *buf
    i:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
    <span class="Delimiter">{</span>
      done?:boolean<span class="Special"> &lt;- </span>greater-or-equal i, max
      <span class="muControl">break-if</span> done?
      curr:screen-cell<span class="Special"> &lt;- </span>merge <span class="Constant">0/empty</span>, <span class="Constant">7/white</span>
      *buf<span class="Special"> &lt;- </span>put-index *buf, i, curr
      i<span class="Special"> &lt;- </span>add i, <span class="Constant">1</span>
      <span class="muControl">loop</span>
    <span class="Delimiter">}</span>
    <span class="Comment"># reset cursor</span>
    *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-row:offset</span>, <span class="Constant">0</span>
    *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, <span class="Constant">0</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  clear-display
]

<span class="muRecipe">def</span> sync-screen screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-if</span> screen
    sync-display
  <span class="Delimiter">}</span>
  <span class="Comment"># do nothing for fake screens</span>
]

<span class="muRecipe">def</span> fake-screen-is-empty? screen:address:screen<span class="muRecipe"> -&gt; </span>result:boolean [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="muControl">return-unless</span> screen, <span class="Constant">1/true</span>
  buf:address:array:screen-cell<span class="Special"> &lt;- </span>get *screen, <span class="Constant">data:offset</span>
  i:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
  len:number<span class="Special"> &lt;- </span>length *buf
  <span class="Delimiter">{</span>
    done?:boolean<span class="Special"> &lt;- </span>greater-or-equal i, len
    <span class="muControl">break-if</span> done?
    curr:screen-cell<span class="Special"> &lt;- </span>index *buf, i
    curr-contents:character<span class="Special"> &lt;- </span>get curr, <span class="Constant">contents:offset</span>
    i<span class="Special"> &lt;- </span>add i, <span class="Constant">1</span>
    <span class="muControl">loop-unless</span> curr-contents
    <span class="Comment"># not 0</span>
    <span class="muControl">return</span> <span class="Constant">0/false</span>
  <span class="Delimiter">}</span>
  <span class="muControl">return</span> <span class="Constant">1/true</span>
]

<span class="muRecipe">def</span> print screen:address:screen, c:character<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  color:number, color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default color to white</span>
    <span class="muControl">break-if</span> color-found?
    color<span class="Special"> &lt;- </span>copy <span class="Constant">7/white</span>
  <span class="Delimiter">}</span>
  bg-color:number, bg-color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default bg-color to black</span>
    <span class="muControl">break-if</span> bg-color-found?
    bg-color<span class="Special"> &lt;- </span>copy <span class="Constant">0/black</span>
  <span class="Delimiter">}</span>
  trace <span class="Constant">90</span>, <span class="Constant">[print-character]</span>, c
  <span class="Delimiter">{</span>
    <span class="Comment"># if x exists</span>
    <span class="Comment"># (handle special cases exactly like in the real screen)</span>
    <span class="muControl">break-unless</span> screen
    width:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-columns:offset</span>
    height:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-rows:offset</span>
    <span class="Comment"># if cursor is out of bounds, silently exit</span>
    row:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-row:offset</span>
    legal?:boolean<span class="Special"> &lt;- </span>greater-or-equal row, <span class="Constant">0</span>
    <span class="muControl">return-unless</span> legal?
    legal?<span class="Special"> &lt;- </span>lesser-than row, height
    <span class="muControl">return-unless</span> legal?
    column:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-column:offset</span>
    legal?<span class="Special"> &lt;- </span>greater-or-equal column, <span class="Constant">0</span>
    <span class="muControl">return-unless</span> legal?
    legal?<span class="Special"> &lt;- </span>lesser-than column, width
    <span class="muControl">return-unless</span> legal?
<span class="CommentedCode">#?     $print [print-character (], row, [, ], column, [): ], c, 10/newline</span>
    <span class="Comment"># special-case: newline</span>
    <span class="Delimiter">{</span>
      newline?:boolean<span class="Special"> &lt;- </span>equal c, <span class="Constant">10/newline</span>
      <span class="muControl">break-unless</span> newline?
      <span class="Delimiter">{</span>
        <span class="Comment"># unless cursor is already at bottom</span>
        bottom:number<span class="Special"> &lt;- </span>subtract height, <span class="Constant">1</span>
        at-bottom?:boolean<span class="Special"> &lt;- </span>greater-or-equal row, bottom
        <span class="muControl">break-if</span> at-bottom?
        <span class="Comment"># move it to the next row</span>
        column<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
        *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, column
        row<span class="Special"> &lt;- </span>add row, <span class="Constant">1</span>
        *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-row:offset</span>, row
      <span class="Delimiter">}</span>
      <span class="muControl">return</span>
    <span class="Delimiter">}</span>
    <span class="Comment"># save character in fake screen</span>
    index:number<span class="Special"> &lt;- </span>multiply row, width
    index<span class="Special"> &lt;- </span>add index, column
    buf:address:array:screen-cell<span class="Special"> &lt;- </span>get *screen, <span class="Constant">data:offset</span>
    len:number<span class="Special"> &lt;- </span>length *buf
    <span class="Comment"># special-case: backspace</span>
    <span class="Delimiter">{</span>
      backspace?:boolean<span class="Special"> &lt;- </span>equal c, <span class="Constant">8</span>
      <span class="muControl">break-unless</span> backspace?
      <span class="Delimiter">{</span>
        <span class="Comment"># unless cursor is already at left margin</span>
        at-left?:boolean<span class="Special"> &lt;- </span>lesser-or-equal column, <span class="Constant">0</span>
        <span class="muControl">break-if</span> at-left?
        <span class="Comment"># clear previous location</span>
        column<span class="Special"> &lt;- </span>subtract column, <span class="Constant">1</span>
        *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, column
        index<span class="Special"> &lt;- </span>subtract index, <span class="Constant">1</span>
        cursor:screen-cell<span class="Special"> &lt;- </span>merge <span class="Constant">32/space</span>, <span class="Constant">7/white</span>
        *buf<span class="Special"> &lt;- </span>put-index *buf, index, cursor
      <span class="Delimiter">}</span>
      <span class="muControl">return</span>
    <span class="Delimiter">}</span>
    cursor:screen-cell<span class="Special"> &lt;- </span>merge c, color
    *buf<span class="Special"> &lt;- </span>put-index *buf, index, cursor
    <span class="Comment"># increment column unless it's already all the way to the right</span>
    <span class="Delimiter">{</span>
      right:number<span class="Special"> &lt;- </span>subtract width, <span class="Constant">1</span>
      at-right?:boolean<span class="Special"> &lt;- </span>greater-or-equal column, right
      <span class="muControl">break-if</span> at-right?
      column<span class="Special"> &lt;- </span>add column, <span class="Constant">1</span>
      *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, column
    <span class="Delimiter">}</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  print-character-to-display c, color, bg-color
]

<span class="muScenario">scenario</span> print-character-at-top-left [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a
    <span class="Constant">2</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">3</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">2</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">3</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">4</span><span class="Special"> &lt;- </span><span class="Constant">97</span>  <span class="Comment"># 'a'</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muScenario">scenario</span> print-character-in-color [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a, <span class="Constant">1/red</span>
    <span class="Constant">2</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">3</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">2</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">3</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">4</span><span class="Special"> &lt;- </span><span class="Constant">97</span>  <span class="Comment"># 'a'</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">1</span>  <span class="Comment"># red</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muScenario">scenario</span> print-backspace-character [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a
    <span class="Constant">12</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">8/backspace</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">12</span>:character/backspace
    <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-column:offset</span>
    <span class="Constant">3</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">4</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">3</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">2</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># cursor column</span>
    <span class="Constant">4</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">32</span>  <span class="Comment"># space, not 'a'</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">7</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muScenario">scenario</span> print-extra-backspace-character [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a
    <span class="Constant">12</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">8/backspace</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">12</span>:character/backspace
    <span class="Constant">12</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">8/backspace</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">12</span>:character/backspace
    <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-column:offset</span>
    <span class="Constant">3</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">4</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">3</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">2</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># cursor column</span>
    <span class="Constant">4</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">32</span>  <span class="Comment"># space, not 'a'</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">7</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muScenario">scenario</span> print-character-at-right-margin [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">2/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a
    <span class="Constant">12</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">98/b</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">12</span>:character/b
    <span class="Constant">13</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">99/b</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">13</span>:character/c
    <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-column:offset</span>
    <span class="Constant">3</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">4</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">3</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">2</span><span class="Special"> &lt;- </span><span class="Constant">1</span>  <span class="Comment"># cursor column</span>
    <span class="Constant">4</span><span class="Special"> &lt;- </span><span class="Constant">4</span>  <span class="Comment"># width*height</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">97</span>  <span class="Comment"># 'a'</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">7</span><span class="Special"> &lt;- </span><span class="Constant">99</span>  <span class="Comment"># 'c' over 'b'</span>
    <span class="Constant">8</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">9</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muScenario">scenario</span> print-newline-character [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">10</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">10/newline</span>
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/newline
    <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-row:offset</span>
    <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-column:offset</span>
    <span class="Constant">4</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">5</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">4</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">2</span><span class="Special"> &lt;- </span><span class="Constant">1</span>  <span class="Comment"># cursor row</span>
    <span class="Constant">3</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># cursor column</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">97</span>  <span class="Comment"># 'a'</span>
    <span class="Constant">7</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">8</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muScenario">scenario</span> print-newline-at-bottom-line [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">10</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">10/newline</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/newline
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/newline
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/newline
    <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-row:offset</span>
    <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-column:offset</span>
  ]
  memory-should-contain [
    <span class="Constant">2</span><span class="Special"> &lt;- </span><span class="Constant">1</span>  <span class="Comment"># cursor row</span>
    <span class="Constant">3</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># cursor column</span>
  ]
]

<span class="muScenario">scenario</span> print-character-at-bottom-right [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">2/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">10</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">10/newline</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/newline
    <span class="Constant">11</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">11</span>:character/a
    <span class="Constant">12</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">98/b</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">12</span>:character/b
    <span class="Constant">13</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">99/c</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">13</span>:character/c
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/newline
    <span class="Constant">14</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">100/d</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">14</span>:character/d
    <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-row:offset</span>
    <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">cursor-column:offset</span>
    <span class="Constant">4</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">20</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">4</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">2</span><span class="Special"> &lt;- </span><span class="Constant">1</span>  <span class="Comment"># cursor row</span>
    <span class="Constant">3</span><span class="Special"> &lt;- </span><span class="Constant">1</span>  <span class="Comment"># cursor column</span>
    <span class="Constant">20</span><span class="Special"> &lt;- </span><span class="Constant">4</span>  <span class="Comment"># width*height</span>
    <span class="Constant">21</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># unused</span>
    <span class="Constant">22</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">23</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># unused</span>
    <span class="Constant">24</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">25</span><span class="Special"> &lt;- </span><span class="Constant">97</span> <span class="Comment"># 'a'</span>
    <span class="Constant">26</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">27</span><span class="Special"> &lt;- </span><span class="Constant">100</span>  <span class="Comment"># 'd' over 'b' and 'c' and newline</span>
    <span class="Constant">28</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">29</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
  ]
]

<span class="muRecipe">def</span> clear-line screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  space:character<span class="Special"> &lt;- </span>copy <span class="Constant">0/nul</span>
  <span class="Comment"># if x exists, clear line in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    width:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-columns:offset</span>
    column:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-column:offset</span>
    original-column:number<span class="Special"> &lt;- </span>copy column
    <span class="Comment"># space over the entire line</span>
    <span class="Delimiter">{</span>
      right:number<span class="Special"> &lt;- </span>subtract width, <span class="Constant">1</span>
      done?:boolean<span class="Special"> &lt;- </span>greater-or-equal column, right
      <span class="muControl">break-if</span> done?
      print screen, space
      column<span class="Special"> &lt;- </span>add column, <span class="Constant">1</span>
      <span class="muControl">loop</span>
    <span class="Delimiter">}</span>
    <span class="Comment"># now back to where the cursor was</span>
    *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, original-column
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  clear-line-on-display
]

<span class="muRecipe">def</span> cursor-position screen:address:screen<span class="muRecipe"> -&gt; </span>row:number, column:number [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, lookup cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    row:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-row:offset</span>
    column:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-column:offset</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  row, column<span class="Special"> &lt;- </span>cursor-position-on-display
]

<span class="muRecipe">def</span> move-cursor screen:address:screen, new-row:number, new-column:number<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-row:offset</span>, new-row
    *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, new-column
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-on-display new-row, new-column
]

<span class="muScenario">scenario</span> clear-line-erases-printed-characters [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Comment"># print a character</span>
    <span class="Constant">10</span>:character<span class="Special"> &lt;- </span>copy <span class="Constant">97/a</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">10</span>:character/a
    <span class="Comment"># move cursor to start of line</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>move-cursor <span class="Constant">1</span>:address:screen, <span class="Constant">0/row</span>, <span class="Constant">0/column</span>
    <span class="Comment"># clear line</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>clear-line <span class="Constant">1</span>:address:screen
    <span class="Constant">2</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">20</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">2</span>:address:array:screen-cell
  ]
  <span class="Comment"># screen should be blank</span>
  memory-should-contain [
    <span class="Constant">20</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">21</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
    <span class="Constant">22</span><span class="Special"> &lt;- </span><span class="Constant">7</span>
    <span class="Constant">23</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
    <span class="Constant">24</span><span class="Special"> &lt;- </span><span class="Constant">7</span>
    <span class="Constant">25</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
    <span class="Constant">26</span><span class="Special"> &lt;- </span><span class="Constant">7</span>
    <span class="Constant">27</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
    <span class="Constant">28</span><span class="Special"> &lt;- </span><span class="Constant">7</span>
    <span class="Constant">29</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
    <span class="Constant">30</span><span class="Special"> &lt;- </span><span class="Constant">7</span>
    <span class="Constant">31</span><span class="Special"> &lt;- </span><span class="Constant">0</span>
    <span class="Constant">32</span><span class="Special"> &lt;- </span><span class="Constant">7</span>
  ]
]

<span class="muRecipe">def</span> cursor-down screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="Delimiter">{</span>
      <span class="Comment"># increment row unless it's already all the way down</span>
      height:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-rows:offset</span>
      row:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-row:offset</span>
      max:number<span class="Special"> &lt;- </span>subtract height, <span class="Constant">1</span>
      at-bottom?:boolean<span class="Special"> &lt;- </span>greater-or-equal row, max
      <span class="muControl">break-if</span> at-bottom?
      row<span class="Special"> &lt;- </span>add row, <span class="Constant">1</span>
      *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-row:offset</span>, row
    <span class="Delimiter">}</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-down-on-display
]

<span class="muRecipe">def</span> cursor-up screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="Delimiter">{</span>
      <span class="Comment"># decrement row unless it's already all the way up</span>
      row:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-row:offset</span>
      at-top?:boolean<span class="Special"> &lt;- </span>lesser-or-equal row, <span class="Constant">0</span>
      <span class="muControl">break-if</span> at-top?
      row<span class="Special"> &lt;- </span>subtract row, <span class="Constant">1</span>
      *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-row:offset</span>, row
    <span class="Delimiter">}</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-up-on-display
]

<span class="muRecipe">def</span> cursor-right screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="Delimiter">{</span>
      <span class="Comment"># increment column unless it's already all the way to the right</span>
      width:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-columns:offset</span>
      column:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-column:offset</span>
      max:number<span class="Special"> &lt;- </span>subtract width, <span class="Constant">1</span>
      at-bottom?:boolean<span class="Special"> &lt;- </span>greater-or-equal column, max
      <span class="muControl">break-if</span> at-bottom?
      column<span class="Special"> &lt;- </span>add column, <span class="Constant">1</span>
      *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, column
    <span class="Delimiter">}</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-right-on-display
]

<span class="muRecipe">def</span> cursor-left screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="Delimiter">{</span>
      <span class="Comment"># decrement column unless it's already all the way to the left</span>
      column:number<span class="Special"> &lt;- </span>get *screen, <span class="Constant">cursor-column:offset</span>
      at-top?:boolean<span class="Special"> &lt;- </span>lesser-or-equal column, <span class="Constant">0</span>
      <span class="muControl">break-if</span> at-top?
      column<span class="Special"> &lt;- </span>subtract column, <span class="Constant">1</span>
      *screen<span class="Special"> &lt;- </span>put *screen, <span class="Constant">cursor-column:offset</span>, column
    <span class="Delimiter">}</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-left-on-display
]

<span class="muRecipe">def</span> cursor-to-start-of-line screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  row:number<span class="Special"> &lt;- </span>cursor-position screen
  column:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
  screen<span class="Special"> &lt;- </span>move-cursor screen, row, column
]

<span class="muRecipe">def</span> cursor-to-next-line screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  screen<span class="Special"> &lt;- </span>cursor-down screen
  screen<span class="Special"> &lt;- </span>cursor-to-start-of-line screen
]

<span class="muRecipe">def</span> screen-width screen:address:screen<span class="muRecipe"> -&gt; </span>width:number [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    width<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-columns:offset</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  width<span class="Special"> &lt;- </span>display-width
]

<span class="muRecipe">def</span> screen-height screen:address:screen<span class="muRecipe"> -&gt; </span>height:number [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    height<span class="Special"> &lt;- </span>get *screen, <span class="Constant">num-rows:offset</span>
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  height<span class="Special"> &lt;- </span>display-height
]

<span class="muRecipe">def</span> hide-cursor screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists (not real display), do nothing</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  hide-cursor-on-display
]

<span class="muRecipe">def</span> show-cursor screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists (not real display), do nothing</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  show-cursor-on-display
]

<span class="muRecipe">def</span> hide-screen screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists (not real display), do nothing</span>
  <span class="Comment"># todo: help test this</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  hide-display
]

<span class="muRecipe">def</span> show-screen screen:address:screen<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># if x exists (not real display), do nothing</span>
  <span class="Comment"># todo: help test this</span>
  <span class="Delimiter">{</span>
    <span class="muControl">break-unless</span> screen
    <span class="muControl">return</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  show-display
]

<span class="muRecipe">def</span> print screen:address:screen, s:address:array:character<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  color:number, color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default color to white</span>
    <span class="muControl">break-if</span> color-found?
    color<span class="Special"> &lt;- </span>copy <span class="Constant">7/white</span>
  <span class="Delimiter">}</span>
  bg-color:number, bg-color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default bg-color to black</span>
    <span class="muControl">break-if</span> bg-color-found?
    bg-color<span class="Special"> &lt;- </span>copy <span class="Constant">0/black</span>
  <span class="Delimiter">}</span>
  len:number<span class="Special"> &lt;- </span>length *s
  i:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
  <span class="Delimiter">{</span>
    done?:boolean<span class="Special"> &lt;- </span>greater-or-equal i, len
    <span class="muControl">break-if</span> done?
    c:character<span class="Special"> &lt;- </span>index *s, i
    print screen, c, color, bg-color
    i<span class="Special"> &lt;- </span>add i, <span class="Constant">1</span>
    <span class="muControl">loop</span>
  <span class="Delimiter">}</span>
]

<span class="muScenario">scenario</span> print-text-stops-at-right-margin [
  run [
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>new-fake-screen <span class="Constant">3/width</span>, <span class="Constant">2/height</span>
    <span class="Constant">2</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abcd]</span>
    <span class="Constant">1</span>:address:screen<span class="Special"> &lt;- </span>print <span class="Constant">1</span>:address:screen, <span class="Constant">2</span>:address:array:character
    <span class="Constant">3</span>:address:array:screen-cell<span class="Special"> &lt;- </span>get *<span class="Constant">1</span>:address:screen, <span class="Constant">data:offset</span>
    <span class="Constant">4</span>:array:screen-cell<span class="Special"> &lt;- </span>copy *<span class="Constant">3</span>:address:array:screen-cell
  ]
  memory-should-contain [
    <span class="Constant">4</span><span class="Special"> &lt;- </span><span class="Constant">6</span>  <span class="Comment"># width*height</span>
    <span class="Constant">5</span><span class="Special"> &lt;- </span><span class="Constant">97</span>  <span class="Comment"># 'a'</span>
    <span class="Constant">6</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">7</span><span class="Special"> &lt;- </span><span class="Constant">98</span>  <span class="Comment"># 'b'</span>
    <span class="Constant">8</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">9</span><span class="Special"> &lt;- </span><span class="Constant">100</span>  <span class="Comment"># 'd' overwrites 'c'</span>
    <span class="Constant">10</span><span class="Special"> &lt;- </span><span class="Constant">7</span>  <span class="Comment"># white</span>
    <span class="Constant">11</span><span class="Special"> &lt;- </span><span class="Constant">0</span>  <span class="Comment"># unused</span>
  ]
]

<span class="muRecipe">def</span> print-integer screen:address:screen, n:number<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  color:number, color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default color to white</span>
    <span class="muControl">break-if</span> color-found?
    color<span class="Special"> &lt;- </span>copy <span class="Constant">7/white</span>
  <span class="Delimiter">}</span>
  bg-color:number, bg-color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default bg-color to black</span>
    <span class="muControl">break-if</span> bg-color-found?
    bg-color<span class="Special"> &lt;- </span>copy <span class="Constant">0/black</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># todo: other bases besides decimal</span>
  s:address:array:character<span class="Special"> &lt;- </span>to-text n
  screen<span class="Special"> &lt;- </span>print screen, s, color, bg-color
]

<span class="Comment"># for now, we can only print integers</span>
<span class="muRecipe">def</span> print screen:address:screen, n:number<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  color:number, color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default color to white</span>
    <span class="muControl">break-if</span> color-found?
    color<span class="Special"> &lt;- </span>copy <span class="Constant">7/white</span>
  <span class="Delimiter">}</span>
  bg-color:number, bg-color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default bg-color to black</span>
    <span class="muControl">break-if</span> bg-color-found?
    bg-color<span class="Special"> &lt;- </span>copy <span class="Constant">0/black</span>
  <span class="Delimiter">}</span>
  screen<span class="Special"> &lt;- </span>print-integer screen, n, color, bg-color
]

<span class="Comment"># addresses</span>
<span class="muRecipe">def</span> print screen:address:screen, n:address:_elem<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  color:number, color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default color to white</span>
    <span class="muControl">break-if</span> color-found?
    color<span class="Special"> &lt;- </span>copy <span class="Constant">7/white</span>
  <span class="Delimiter">}</span>
  bg-color:number, bg-color-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
  <span class="Delimiter">{</span>
    <span class="Comment"># default bg-color to black</span>
    <span class="muControl">break-if</span> bg-color-found?
    bg-color<span class="Special"> &lt;- </span>copy <span class="Constant">0/black</span>
  <span class="Delimiter">}</span>
  n2:number<span class="Special"> &lt;- </span>copy n
  screen<span class="Special"> &lt;- </span>print-integer screen, n2, color, bg-color
]
</pre>
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