about summary refs log tree commit diff stats
path: root/html/071print.mu.html
blob: 2e0c0dee095a0df92a8a68a8f137e83fb895a9e4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
<!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>~/Desktop/s/mu/071print.mu</title>
<meta name="Generator" content="Vim/7.4">
<meta name="plugin-version" content="vim7.4_v1">
<meta name="syntax" content="none">
<meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #d0d0d0; background-color: #000000; }
body { font-family: monospace; color: #d0d0d0; background-color: #000000; }
* { font-size: 1em; }
.CommentedCode { color: #6c6c6c; }
.Delimiter { color: #c000c0; }
.Comment { color: #8080ff; }
.Constant { color: #008080; }
.Special { color: #ff6060; }
.Identifier { color: #008080; }
-->
</style>

<script type='text/javascript'>
<!--

-->
</script>
</head>
<body>
<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>

container screen [
  num-rows:number
  num-columns:number
  cursor-row:number
  cursor-column:number
  data:address:array:character
]

recipe init-fake-screen [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal/capacity</span>
  result:address:screen<span class="Special"> &lt;- </span>new screen:type
  width:address:number<span class="Special"> &lt;- </span>get-address result:address:screen/deref, num-columns:offset
  width:address:number/deref<span class="Special"> &lt;- </span>next-ingredient
  height:address:number<span class="Special"> &lt;- </span>get-address result:address:screen/deref, num-rows:offset
  height:address:number/deref<span class="Special"> &lt;- </span>next-ingredient
  row:address:number<span class="Special"> &lt;- </span>get-address result:address:screen/deref, cursor-row:offset
  row:address:number/deref<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
  column:address:number<span class="Special"> &lt;- </span>get-address result:address:screen/deref, cursor-column:offset
  column:address:number/deref<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
  bufsize:number<span class="Special"> &lt;- </span>multiply width:address:number/deref, height:address:number/deref
  buf:address:address:array:character<span class="Special"> &lt;- </span>get-address result:address:screen/deref, data:offset
  buf:address:address:array:character/deref<span class="Special"> &lt;- </span>new <span class="Constant">character:literal</span>, bufsize:number
  clear-screen result:address:screen
  <span class="Identifier">reply</span> result:address:screen
]

recipe clear-screen [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
<span class="CommentedCode">#?   $print [clearing screen</span>
<span class="CommentedCode">#? ] #? 1</span>
  <span class="Comment"># if x exists</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    <span class="Comment"># clear fake screen</span>
    buf:address:array:character<span class="Special"> &lt;- </span>get x:address:screen/deref, data:offset
    max:number<span class="Special"> &lt;- </span>length buf:address:array:character/deref
    i:number<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
    <span class="Delimiter">{</span>
      done?:boolean<span class="Special"> &lt;- </span>greater-or-equal i:number, max:number
      <span class="Identifier">break-if</span> done?:boolean
      c:address:character<span class="Special"> &lt;- </span>index-address buf:address:array:character/deref, i:number
      c:address:character/deref<span class="Special"> &lt;- </span>copy <span class="Constant">[ ]</span>
      i:number<span class="Special"> &lt;- </span>add i:number, <span class="Constant">1:literal</span>
      <span class="Identifier">loop</span>
    <span class="Delimiter">}</span>
    <span class="Comment"># reset cursor</span>
    cur:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-row:offset
    cur:address:number/deref<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
    cur:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-column:offset
    cur:address:number/deref<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  clear-display
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe print-character [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  c:character<span class="Special"> &lt;- </span>next-ingredient
  <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="Identifier">break-unless</span> x:address:screen
    row:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-row:offset
    column:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-column:offset
    width:number<span class="Special"> &lt;- </span>get x:address:screen/deref, num-columns:offset
    height:number<span class="Special"> &lt;- </span>get x:address:screen/deref, num-rows:offset
    max-row:number<span class="Special"> &lt;- </span>subtract height:number, <span class="Constant">1:literal</span>
    <span class="Comment"># special-case: newline</span>
    <span class="Delimiter">{</span>
      newline?:boolean<span class="Special"> &lt;- </span>equal c:character, <span class="Constant">10:literal/newlin</span>
<span class="CommentedCode">#?       $print c:character, [ ], newline?:boolean, [ </span>
<span class="CommentedCode">#? ] #? 1</span>
      <span class="Identifier">break-unless</span> newline?:boolean
      <span class="Delimiter">{</span>
        <span class="Comment"># unless cursor is already at bottom</span>
        at-bottom?:boolean<span class="Special"> &lt;- </span>greater-or-equal row:address:number/deref, max-row:number
        <span class="Identifier">break-if</span> at-bottom?:boolean
        <span class="Comment"># move it to the next row</span>
        column:address:number/deref<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
        row:address:number/deref<span class="Special"> &lt;- </span>add row:address:number/deref, <span class="Constant">1:literal</span>
      <span class="Delimiter">}</span>
      <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
    <span class="Delimiter">}</span>
    <span class="Comment"># save character in fake screen</span>
    index:number<span class="Special"> &lt;- </span>multiply row:address:number/deref, width:number
    index:number<span class="Special"> &lt;- </span>add index:number, column:address:number/deref
    buf:address:array:character<span class="Special"> &lt;- </span>get x:address:screen/deref, data:offset
    cursor:address:character<span class="Special"> &lt;- </span>index-address buf:address:array:character/deref, index:number
    <span class="Comment"># special-case: backspace</span>
    <span class="Delimiter">{</span>
      backspace?:boolean<span class="Special"> &lt;- </span>equal c:character, <span class="Constant">8:literal</span>
      <span class="Identifier">break-unless</span> backspace?:boolean
      <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:address:number/deref, <span class="Constant">0:literal</span>
        <span class="Identifier">break-if</span> at-left?:boolean
        <span class="Comment"># clear previous location</span>
        column:address:number/deref<span class="Special"> &lt;- </span>subtract column:address:number/deref, <span class="Constant">1:literal</span>
        cursor:address:character<span class="Special"> &lt;- </span>subtract cursor:address:character, <span class="Constant">1:literal</span>
        cursor:address:character/deref<span class="Special"> &lt;- </span>copy <span class="Constant">32:literal/space</span>
      <span class="Delimiter">}</span>
      <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
    <span class="Delimiter">}</span>
<span class="CommentedCode">#?     $print [saving character ], c:character, [ to fake screen ], cursor:address/screen, [ </span>
<span class="CommentedCode">#? ] #? 1</span>
    cursor:address:character/deref<span class="Special"> &lt;- </span>copy c:character
    <span class="Comment"># increment column unless it's already all the way to the right</span>
    <span class="Delimiter">{</span>
      at-right?:boolean<span class="Special"> &lt;- </span>equal column:address:number/deref, width:number
      <span class="Identifier">break-if</span> at-right?:boolean
      column:address:number/deref<span class="Special"> &lt;- </span>add column:address:number/deref, <span class="Constant">1:literal</span>
    <span class="Delimiter">}</span>
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  print-character-to-display c:character
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

scenario print-character-at-top-left [
  run [
<span class="CommentedCode">#?     $start-tracing #? 3</span>
    1:address:screen<span class="Special"> &lt;- </span>init-fake-screen <span class="Constant">3:literal/width</span>, <span class="Constant">2:literal/height</span>
    1:address:screen<span class="Special"> &lt;- </span>print-character 1:address:screen, <span class="Constant">97:literal</span>  <span class="Comment"># 'a'</span>
    2:address:array:character<span class="Special"> &lt;- </span>get 1:address:screen/deref, data:offset
    3:array:character<span class="Special"> &lt;- </span>copy 2:address:array:character/deref
  ]
  memory-should-contain [
    3<span class="Special"> &lt;- </span>6  <span class="Comment"># width*height</span>
    4<span class="Special"> &lt;- </span>97  <span class="Comment"># 'a'</span>
    5<span class="Special"> &lt;- </span>0
  ]
]

scenario print-backspace-character [
  run [
<span class="CommentedCode">#?     $start-tracing #? 3</span>
    1:address:screen<span class="Special"> &lt;- </span>init-fake-screen <span class="Constant">3:literal/width</span>, <span class="Constant">2:literal/height</span>
    1:address:screen<span class="Special"> &lt;- </span>print-character 1:address:screen, <span class="Constant">97:literal</span>  <span class="Comment"># 'a'</span>
    1:address:screen<span class="Special"> &lt;- </span>print-character 1:address:screen, <span class="Constant">8:literal</span>  <span class="Comment"># backspace</span>
    2:number<span class="Special"> &lt;- </span>get 1:address:screen/deref, cursor-column:offset
    3:address:array:character<span class="Special"> &lt;- </span>get 1:address:screen/deref, data:offset
    4:array:character<span class="Special"> &lt;- </span>copy 3:address:array:character/deref
  ]
  memory-should-contain [
    2<span class="Special"> &lt;- </span>0  <span class="Comment"># cursor column</span>
    4<span class="Special"> &lt;- </span>6  <span class="Comment"># width*height</span>
    5<span class="Special"> &lt;- </span>32  <span class="Comment"># space, not 'a'</span>
    6<span class="Special"> &lt;- </span>0
  ]
]

scenario print-newline-character [
  run [
<span class="CommentedCode">#?     $start-tracing #? 3</span>
    1:address:screen<span class="Special"> &lt;- </span>init-fake-screen <span class="Constant">3:literal/width</span>, <span class="Constant">2:literal/height</span>
    1:address:screen<span class="Special"> &lt;- </span>print-character 1:address:screen, <span class="Constant">97:literal</span>  <span class="Comment"># 'a'</span>
    1:address:screen<span class="Special"> &lt;- </span>print-character 1:address:screen, <span class="Constant">10:literal/newline</span>
    2:number<span class="Special"> &lt;- </span>get 1:address:screen/deref, cursor-row:offset
    3:number<span class="Special"> &lt;- </span>get 1:address:screen/deref, cursor-column:offset
    4:address:array:character<span class="Special"> &lt;- </span>get 1:address:screen/deref, data:offset
    5:array:character<span class="Special"> &lt;- </span>copy 4:address:array:character/deref
  ]
  memory-should-contain [
    2<span class="Special"> &lt;- </span>1  <span class="Comment"># cursor row</span>
    3<span class="Special"> &lt;- </span>0  <span class="Comment"># cursor column</span>
    5<span class="Special"> &lt;- </span>6  <span class="Comment"># width*height</span>
    6<span class="Special"> &lt;- </span>97  <span class="Comment"># 'a'</span>
    7<span class="Special"> &lt;- </span>0
  ]
]

recipe clear-line [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, clear line in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    n:number<span class="Special"> &lt;- </span>get x:address:screen/deref, num-columns:offset
    column:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-column:offset
    original-column:number<span class="Special"> &lt;- </span>copy column:address:number/deref
    <span class="Comment"># space over the entire line</span>
<span class="CommentedCode">#?     $start-tracing #? 1</span>
    <span class="Delimiter">{</span>
<span class="CommentedCode">#?       $print column:address:number/deref, [ </span>
<span class="CommentedCode">#? ] #? 1</span>
      done?:boolean<span class="Special"> &lt;- </span>greater-or-equal column:address:number/deref, n:number
      <span class="Identifier">break-if</span> done?:boolean
      print-character x:address:screen, <span class="Constant">[ ]</span>  <span class="Comment"># implicitly updates 'column'</span>
      <span class="Identifier">loop</span>
    <span class="Delimiter">}</span>
    <span class="Comment"># now back to where the cursor was</span>
    column:address:number/deref<span class="Special"> &lt;- </span>copy original-column:number
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  clear-line-on-display
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe cursor-position [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, lookup cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    row:number<span class="Special"> &lt;- </span>get x:address:screen/deref, cursor-row:offset
    column:number<span class="Special"> &lt;- </span>get x:address:screen/deref, cursor-column:offset
    <span class="Identifier">reply</span> row:number, column:number, x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  row:number, column:number<span class="Special"> &lt;- </span>cursor-position-on-display
  <span class="Identifier">reply</span> row:number, column:number, x:address:screen/same-as-ingredient:0
]

recipe move-cursor [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  new-row:number<span class="Special"> &lt;- </span>next-ingredient
  new-column:number<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    row:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-row:offset
    row:address:number/deref<span class="Special"> &lt;- </span>copy new-row:number
    column:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-column:offset
    column:address:number/deref<span class="Special"> &lt;- </span>copy new-column:number
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-on-display new-row:number, new-column:number
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

scenario clear-line-erases-printed-characters [
  run [
<span class="CommentedCode">#?     $start-tracing #? 4</span>
    1:address:screen<span class="Special"> &lt;- </span>init-fake-screen <span class="Constant">3:literal/width</span>, <span class="Constant">2:literal/height</span>
    <span class="Comment"># print a character</span>
    1:address:screen<span class="Special"> &lt;- </span>print-character 1:address:screen, <span class="Constant">97:literal</span>  <span class="Comment"># 'a'</span>
    <span class="Comment"># move cursor to start of line</span>
    1:address:screen<span class="Special"> &lt;- </span>move-cursor 1:address:screen, <span class="Constant">0:literal/row</span>, <span class="Constant">0:literal/column</span>
    <span class="Comment"># clear line</span>
    1:address:screen<span class="Special"> &lt;- </span>clear-line 1:address:screen
    2:address:array:character<span class="Special"> &lt;- </span>get 1:address:screen/deref, data:offset
    3:array:character<span class="Special"> &lt;- </span>copy 2:address:array:character/deref
  ]
  <span class="Comment"># screen should be blank</span>
  memory-should-contain [
    3<span class="Special"> &lt;- </span>6  <span class="Comment"># width*height</span>
    4<span class="Special"> &lt;- </span>0
    5<span class="Special"> &lt;- </span>0
    6<span class="Special"> &lt;- </span>0
    7<span class="Special"> &lt;- </span>0
    8<span class="Special"> &lt;- </span>0
    9<span class="Special"> &lt;- </span>0
  ]
]

recipe cursor-down [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    <span class="Delimiter">{</span>
      <span class="Comment"># if row &lt; height</span>
      height:number<span class="Special"> &lt;- </span>get x:address:screen/deref, num-rows:offset
      row:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-row:offset
      at-bottom?:boolean<span class="Special"> &lt;- </span>greater-or-equal row:address:number/deref, height:number
      <span class="Identifier">break-if</span> at-bottom?:boolean
      <span class="Comment"># row = row+1</span>
<span class="CommentedCode">#?       $print [AAA: ], row:address:number, [ -&gt; ], row:address:number/deref, [ </span>
<span class="CommentedCode">#? ] #? 1</span>
      row:address:number/deref<span class="Special"> &lt;- </span>add row:address:number/deref, <span class="Constant">1:literal</span>
<span class="CommentedCode">#?       $print [BBB: ], row:address:number, [ -&gt; ], row:address:number/deref, [ </span>
<span class="CommentedCode">#? ] #? 1</span>
<span class="CommentedCode">#?       $start-tracing #? 1</span>
    <span class="Delimiter">}</span>
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-down-on-display
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe cursor-up [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    <span class="Delimiter">{</span>
      <span class="Comment"># if row &gt;= 0</span>
      row:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-row:offset
      at-top?:boolean<span class="Special"> &lt;- </span>lesser-than row:address:number/deref, <span class="Constant">0:literal</span>
      <span class="Identifier">break-if</span> at-top?:boolean
      <span class="Comment"># row = row-1</span>
      row:address:number/deref<span class="Special"> &lt;- </span>subtract row:address:number/deref, <span class="Constant">1:literal</span>
    <span class="Delimiter">}</span>
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-up-on-display
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe cursor-right [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    <span class="Delimiter">{</span>
      <span class="Comment"># if column &lt; width</span>
      width:number<span class="Special"> &lt;- </span>get x:address:screen/deref, num-columns:offset
      column:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-column:offset
      at-bottom?:boolean<span class="Special"> &lt;- </span>greater-or-equal column:address:number/deref, width:number
      <span class="Identifier">break-if</span> at-bottom?:boolean
      <span class="Comment"># column = column+1</span>
      column:address:number/deref<span class="Special"> &lt;- </span>add column:address:number/deref, <span class="Constant">1:literal</span>
    <span class="Delimiter">}</span>
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-right-on-display
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe cursor-left [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># if x exists, move cursor in fake screen</span>
  <span class="Delimiter">{</span>
    <span class="Identifier">break-unless</span> x:address:screen
    <span class="Delimiter">{</span>
      <span class="Comment"># if column &gt;= 0</span>
      column:address:number<span class="Special"> &lt;- </span>get-address x:address:screen/deref, cursor-column:offset
      at-top?:boolean<span class="Special"> &lt;- </span>lesser-than column:address:number/deref, <span class="Constant">0:literal</span>
      <span class="Identifier">break-if</span> at-top?:boolean
      <span class="Comment"># column = column-1</span>
      column:address:number/deref<span class="Special"> &lt;- </span>subtract column:address:number/deref, <span class="Constant">1:literal</span>
    <span class="Delimiter">}</span>
    <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
  <span class="Delimiter">}</span>
  <span class="Comment"># otherwise, real screen</span>
  move-cursor-left-on-display
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe cursor-to-start-of-line [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  row:number, _, x:address:screen<span class="Special"> &lt;- </span>cursor-position x:address:screen
  column:number<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>move-cursor x:address:screen, row:number, column:number
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe cursor-to-next-line [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  x:address:screen<span class="Special"> &lt;- </span>cursor-down x:address:screen
  x:address:screen<span class="Special"> &lt;- </span>cursor-to-start-of-line x:address:screen
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe print-string [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  s:address:array:character<span class="Special"> &lt;- </span>next-ingredient
  len:number<span class="Special"> &lt;- </span>length s:address:array:character/deref
  i:number<span class="Special"> &lt;- </span>copy <span class="Constant">0:literal</span>
  <span class="Delimiter">{</span>
    done?:boolean<span class="Special"> &lt;- </span>greater-or-equal i:number, len:number
    <span class="Identifier">break-if</span> done?:boolean
    c:character<span class="Special"> &lt;- </span>index s:address:array:character/deref, i:number
    print-character x:address:screen c:character
    i:number<span class="Special"> &lt;- </span>add i:number, <span class="Constant">1:literal</span>
    <span class="Identifier">loop</span>
  <span class="Delimiter">}</span>
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]

recipe print-integer [
  default-space:address:array:location<span class="Special"> &lt;- </span>new location:type, <span class="Constant">30:literal</span>
  x:address:screen<span class="Special"> &lt;- </span>next-ingredient
  n:number<span class="Special"> &lt;- </span>next-ingredient
  <span class="Comment"># todo: other bases besides decimal</span>
  s:address:array:character<span class="Special"> &lt;- </span>integer-to-decimal-string n:number
  print-string x:address:screen, s:address:array:character
  <span class="Identifier">reply</span> x:address:screen/same-as-ingredient:0
]
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->