sible and rewrite-friendly software → More resilient society.
about summary refs log tree commit diff stats
path: root/repl.mu
blob: 59aa68509f29d6ba38024198f67a6dd69b9689a5 (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
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
# interactive prompt for mu

recipe main [
  default-space:address:array:location <- new location:type, 30:literal
  open-console
  msg:address:array:character <- new [ready! type in an instruction, then hit enter. ctrl-d exits.
]
  0:literal/real-screen <- print-string 0:literal/real-screen, msg:address:array:character, 245:literal/grey
  0:literal/real-console, 0:literal/real-screen <- color-session 0:literal/real-console, 0:literal/real-screen
  close-console
]

recipe color-session [
  default-space:address:array:location <- new location:type, 30:literal
  console:address <- next-ingredient
  screen:address <- next-ingredient
  {
    inst:address:array:character, console:address, screen:address <- read-instruction console:address, screen:address
    break-unless inst:address:array:character
    run-interactive inst:address:array:character
    loop
  }
  reply console:address/same-as-ingredient:0, screen:address/same-as-ingredient:1
]

# basic console input; just text and enter
scenario read-instruction1 [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [x <- copy y
]
  ]
  run [
    1:address:array:character <- read-instruction console:address, screen:address
    2:address:array:character <- new [=> ]
    print-string screen:address, 2:address:array:character
    print-string screen:address, 1:address:array:character
  ]
  screen-should-contain [
    .x <- copy y                   .
    .=> x <- copy y                .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .x    copy y                   .
    .=> x <- copy y                .
    .                              .
  ]
  screen-should-contain-in-color 1:literal/red, [
    .  <-                          .
    .                              .
  ]
]

# Read characters as they're typed at the console, print them to the screen,
# accumulate them in a string, return the string at the end.
# Most of the complexity is for the printing to screen, to highlight strings
# and comments specially. Especially in the presence of backspacing.
recipe read-instruction [
  default-space:address:array:location <- new location:type, 60:literal
  console:address <- next-ingredient
  screen:address <- next-ingredient
  result:address:buffer <- new-buffer 10:literal  # string to maybe add to
  trace [app], [read-instruction]
  # start state machine by calling slurp-regular-characters, which will return
  # by calling the complete continuation
  complete:continuation <- current-continuation
  # If result is not empty, we've run slurp-regular-characters below, called
  # the continuation and so bounced back here. We're done.
  len:number <- get result:address:buffer/deref, length:offset
  completed?:boolean <- greater-than len:number, 0:literal
  jump-if completed?:boolean, +completed:label
  # Otherwise we're just getting started.
  result:address:buffer, console:address, screen:address <- slurp-regular-characters result:address:buffer, console:address, screen:address, complete:continuation
#?   $print [aaa: ], result:address:buffer #? 1
#?   move-cursor-down-on-display #? 1
  trace [error], [slurp-regular-characters should never return normally]
  +completed
  result2:address:array:character <- buffer-to-array result:address:buffer
#?   $print [bbb: ], result2:address:array:character #? 1
#?   move-cursor-down-on-display #? 1
  trace [app], [exiting read-instruction]
  reply result2:address:array:character, console:address/same-as-ingredient:0, screen:address/same-as-ingredient:1
]

# read characters from the console, print them to the screen in *white*.
# Transition to other routines for comments and strings.
recipe slurp-regular-characters [
  default-space:address:array:location <- new location:type, 30:literal
  result:address:buffer <- next-ingredient
  console:address <- next-ingredient
  screen:address <- next-ingredient
  complete:continuation <- next-ingredient
  trace [app], [slurp-regular-characters]
  characters-slurped:number <- copy 0:literal
#?   $run-depth #? 1
  {
    +next-character
    trace [app], [slurp-regular-characters: next]
#?     $print [a0 #? 1
#? ] #? 1
#?     move-cursor-down-on-display #? 1
    # read character
    c:character, console:address found?:boolean <- read-key console:address
    loop-unless found?:boolean +next-character:label
#?     print-character screen:address, c:character #? 1
#?     move-cursor-down-on-display #? 1
    # quit?
    {
#?       $print [aaa] #? 1
#?       move-cursor-down-on-display #? 1
      ctrl-d?:boolean <- equal c:character, 4:literal/ctrl-d/eof
      break-unless ctrl-d?:boolean
#?       $print [ctrl-d] #? 1
#?       move-cursor-down-on-display #? 1
      trace [app], [slurp-regular-characters: ctrl-d]
      reply 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    {
      null?:boolean <- equal c:character, 0:literal/null
      break-unless null?:boolean
      trace [app], [slurp-regular-characters: null]
      reply 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    # comment?
    {
      comment?:boolean <- equal c:character, 35:literal/hash
      break-unless comment?:boolean
      print-character screen:address, c:character, 4:literal/blue
      result:address:buffer <- buffer-append result:address:buffer, c:character
      result:address:buffer, console:address, screen:address <- slurp-comment result:address:buffer, console:address, screen:address, complete:continuation
      # continue appending to this instruction, whether comment ended or was backspaced out of
      loop +next-character:label
    }
    # string
    {
      string?:boolean <- equal c:character, 91:literal/open-bracket
      break-unless string?:boolean
      print-character screen:address, c:character, 6:literal/cyan
      result:address:buffer <- buffer-append result:address:buffer, c:character
      result:address:buffer, _, console:address, screen:address <- slurp-string result:address:buffer, console:address, screen:address, complete:continuation
      loop +next-character:label
    }
    # assignment
    {
      assign?:boolean <- equal c:character, 60:literal/less-than
      break-unless assign?:boolean
      print-character screen:address, c:character, 1:literal/red
      trace [app], [start of assignment: <]
      result:address:buffer <- buffer-append result:address:buffer, c:character
      result:address:buffer, console:address, screen:address <- slurp-assignment result:address:buffer, console:address, screen:address, complete:continuation
      loop +next-character:label
    }
    # print
    print-character screen:address, c:character  # default color
    # append
    result:address:buffer <- buffer-append result:address:buffer, c:character
#?     $print [a1 #? 1
#? ] #? 1
#?     move-cursor-down-on-display #? 1
    # backspace? decrement and maybe return
    {
#?       $print [a2 #? 1
#? ] #? 1
#?       move-cursor-down-on-display #? 1
      backspace?:boolean <- equal c:character, 8:literal/backspace
      break-unless backspace?:boolean
#?       $print [a3 #? 1
#? ] #? 1
#?       move-cursor-down-on-display #? 1
      characters-slurped:number <- subtract characters-slurped:number, 1:literal
      {
#?         $print [a4 #? 1
#? ] #? 1
#?         move-cursor-down-on-display #? 1
        done?:boolean <- lesser-or-equal characters-slurped:number, -1:literal
        break-unless done?:boolean
#?         $print [a5 #? 1
#? ] #? 1
#?         move-cursor-down-on-display #? 1
        trace [app], [slurp-regular-characters: too many backspaces; returning]
#?         $print [a6 #? 1
#? ] #? 1
#?         move-cursor-down-on-display #? 1
        reply result:address:buffer, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
      }
      loop +next-character:label
    }
#?     $print [a9 #? 1
#? ] #? 1
#?     move-cursor-down-on-display #? 1
    # otherwise increment
    characters-slurped:number <- add characters-slurped:number, 1:literal
    # done with this instruction?
    done?:boolean <- equal c:character, 10:literal/newline
    break-if done?:boolean
    loop
  }
  # newline encountered; terminate all recursive calls
#?   xx:address:array:character <- new [completing!] #? 1
#?   print-string screen:address, xx:address:array:character #? 1
  trace [app], [slurp-regular-characters: newline encountered; unwinding stack]
  continue-from complete:continuation
]

# read characters from console, print them to screen in the comment color.
#
# Simpler version of slurp-regular-characters; doesn't handle comments or
# strings. Tracks an extra count in case we backspace out of it
recipe slurp-comment [
  default-space:address:array:location <- new location:type, 30:literal
  result:address:buffer <- next-ingredient
  console:address <- next-ingredient
  screen:address <- next-ingredient
  complete:continuation <- next-ingredient
  trace [app], [slurp-comment]
  # use this to track when backspace should reset color
  characters-slurped:number <- copy 1:literal  # for the initial '#' that's already appended to result
  {
    +next-character
    # read character
    c:character, console:address, found?:boolean <- read-key console:address
    loop-unless found?:boolean +next-character:label
    # quit?
    {
      ctrl-d?:boolean <- equal c:character, 4:literal/ctrl-d/eof
      break-unless ctrl-d?:boolean
      trace [app], [slurp-comment: ctrl-d]
      reply 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    {
      null?:boolean <- equal c:character, 0:literal/null
      break-unless null?:boolean
      trace [app], [slurp-comment: null]
      reply 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    # print
    print-character screen:address, c:character, 4:literal/blue
    # append
    result:address:buffer <- buffer-append result:address:buffer, c:character
    # backspace? decrement
    {
      backspace?:boolean <- equal c:character, 8:literal/backspace
      break-unless backspace?:boolean
      characters-slurped:number <- subtract characters-slurped:number, 1:literal
      {
        reset-color?:boolean <- lesser-or-equal characters-slurped:number, 0:literal
        break-unless reset-color?:boolean
        trace [app], [slurp-comment: too many backspaces; returning]
        reply result:address:buffer, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
      }
      loop +next-character:label
    }
    # otherwise increment
    characters-slurped:number <- add characters-slurped:number, 1:literal
    # done with this instruction?
    done?:boolean <- equal c:character, 10:literal/newline
    break-if done?:boolean
    loop
  }
  trace [app], [slurp-regular-characters: newline encountered; unwinding stack]
  continue-from complete:continuation
]

# read characters from console, print them to screen in the string color and
# accumulate them into a buffer.
#
# Version of slurp-regular-characters that:
#   a) doesn't handle comments
#   b) handles nested strings using recursive calls to itself. Tracks an extra
#   count in case we backspace out of it.
recipe slurp-string [
  default-space:address:array:location <- new location:type, 30:literal
  result:address:buffer <- next-ingredient
  console:address <- next-ingredient
  screen:address <- next-ingredient
  complete:continuation <- next-ingredient
  nested-string?:boolean <- next-ingredient
  trace [app], [slurp-string]
  # use this to track when backspace should reset color
  characters-slurped:number <- copy 1:literal  # for the initial '[' that's already appended to result
  {
    +next-character
    # read character
    c:character, console:address, found?:boolean <- read-key console:address
    loop-unless found?:boolean +next-character:label
    # quit?
    {
      ctrl-d?:boolean <- equal c:character, 4:literal/ctrl-d/eof
      break-unless ctrl-d?:boolean
      trace [app], [slurp-string: ctrl-d]
      reply 0:literal, 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    {
      null?:boolean <- equal c:character, 0:literal/null
      break-unless null?:boolean
      trace [app], [slurp-string: null]
      reply 0:literal, 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    # string
    {
      string?:boolean <- equal c:character, 91:literal/open-bracket
      break-unless string?:boolean
      trace [app], [slurp-string: open-bracket encountered; recursing]
      print-character screen:address, c:character, 6:literal/cyan
      result:address:buffer <- buffer-append result:address:buffer, c:character
      # make a recursive call to handle nested strings
      result:address:buffer, tmp:number, console:address, screen:address <- slurp-string result:address:buffer, console:address, screen:address, complete:continuation, 1:literal/nested?
      # but if we backspace over a completed nested string, handle it in the caller
      characters-slurped:number <- add characters-slurped:number, tmp:number, 1:literal  # for the leading '['
      loop +next-character:label
    }
    # print
    print-character screen:address, c:character, 6:literal/cyan
    # append
    result:address:buffer <- buffer-append result:address:buffer, c:character
    # backspace? decrement
    {
      backspace?:boolean <- equal c:character, 8:literal/backspace
      break-unless backspace?:boolean
      characters-slurped:number <- subtract characters-slurped:number, 1:literal
      {
        reset-color?:boolean <- lesser-or-equal characters-slurped:number, 0:literal
        break-unless reset-color?:boolean
        trace [app], [slurp-string: too many backspaces; returning]
        reply result:address:buffer/same-as-ingredient:0, 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
      }
      loop +next-character:label
    }
    # otherwise increment
    characters-slurped:number <- add characters-slurped:number, 1:literal
    # done with this instruction?
    done?:boolean <- equal c:character, 93:literal/close-bracket
    break-if done?:boolean
    loop
  }
  {
    break-unless nested-string?:boolean
    # nested string? return like a normal recipe
    reply result:address:buffer, characters-slurped:number, console:address, screen:address
  }
  # top-level string call? recurse
  trace [app], [slurp-string: close-bracket encountered; recursing to regular characters]
  result:address:buffer, console:address, screen:address <- slurp-regular-characters result:address:buffer, console:address, screen:address, complete:continuation
  # backspaced back into this string
  trace [app], [slurp-string: backspaced back into string; restarting]
  jump +next-character:label
]

recipe slurp-assignment [
  default-space:address:array:location <- new location:type, 30:literal
  result:address:buffer <- next-ingredient
  console:address <- next-ingredient
  screen:address <- next-ingredient
  complete:continuation <- next-ingredient
  {
    +next-character
    # read character
    c:character, console:address, found?:boolean <- read-key console:address
    loop-unless found?:boolean +next-character:label
    # quit?
    {
      ctrl-d?:boolean <- equal c:character, 4:literal/ctrl-d/eof
      break-unless ctrl-d?:boolean
      trace [app], [slurp-assignment: ctrl-d]
      reply 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    {
      null?:boolean <- equal c:character, 0:literal/null
      break-unless null?:boolean
      trace [app], [slurp-assignment: null]
      reply 0:literal, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
    # print
    print-character screen:address, c:character, 1:literal/red
    trace [app], [slurp-assignment: saved one character]
    # append
    result:address:buffer <- buffer-append result:address:buffer, c:character
    # backspace? return
    {
      backspace?:boolean <- equal c:character, 8:literal/backspace
      break-unless backspace?:boolean
      trace [app], [slurp-assignment: backspace; returning]
      reply result:address:buffer/same-as-ingredient:0, console:address/same-as-ingredient:1, screen:address/same-as-ingredient:2
    }
  }
  trace [app], [slurp-assignment: done, recursing to regular characters]
  result:address:buffer, console:address, screen:address <- slurp-regular-characters result:address:buffer, console:address, screen:address, complete:continuation
  # backspaced back into this string
  trace [app], [slurp-assignment: backspaced back into assignment; restarting]
  jump +next-character:label
]

scenario read-instruction-color-comment [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [# comment]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .# comment                     .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .                              .
    .                              .
  ]
]

scenario read-instruction-cancel-comment-on-backspace [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [#a««z]
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .                              .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .z                             .
    .                              .
  ]
]

scenario read-instruction-cancel-comment-on-backspace2 [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [#ab«««z]
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .                              .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .z                             .
    .                              .
  ]
]

scenario read-instruction-cancel-comment-on-backspace3 [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [#a«z]
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .#z                            .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .                              .
    .                              .
  ]
]

scenario read-instruction-stop-after-comment [
  assume-screen 30:literal/width, 5:literal/height
  # console contains comment and then a second line
  assume-console [
    type [#abc
3]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  # check that read-instruction reads just the comment
  screen-should-contain [
    .#abc                          .
    .                              .
  ]
]

scenario read-instruction-color-string [
#?   $start-tracing #? 1
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [abc [string]]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .abc [string]                  .
    .                              .
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .    [string]                  .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .abc                           .
    .                              .
  ]
]

scenario read-instruction-color-string-multiline [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [abc [line1
line2]]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .abc [line1                    .
    .line2]                        .
    .                              .
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .    [line1                    .
    .line2]                        .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .abc                           .
    .                              .
    .                              .
  ]
]

scenario read-instruction-color-string-and-comment [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [abc [string]  # comment]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .abc [string]  # comment       .
    .                              .
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .              # comment       .
    .                              .
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .    [string]                  .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .abc                           .
    .                              .
  ]
]

scenario read-instruction-ignore-comment-inside-string [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [abc [string # not a comment]]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .abc [string # not a comment]  .
    .                              .
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .    [string # not a comment]  .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .abc                           .
    .                              .
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .                              .
    .                              .
  ]
]

scenario read-instruction-ignore-string-inside-comment [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [abc # comment [not a string]]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .abc # comment [not a string]  .
    .                              .
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .                              .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .abc                           .
    .                              .
  ]
  screen-should-contain-in-color 4:literal/blue, [
    .    # comment [not a string]  .
    .                              .
  ]
]

scenario read-instruction-color-string-inside-string [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [abc [string [inner string]]]
  ]
  run [
#?     $start-tracing #? 1
    read-instruction console:address, screen:address
#?     $stop-tracing #? 1
#?     $browse-trace #? 1
  ]
  screen-should-contain [
    .abc [string [inner string]]   .
    .                              .
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .    [string [inner string]]   .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .abc                           .
    .                              .
  ]
]

scenario read-instruction-cancel-string-on-backspace [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [(a««z]  # '(' is '[' and '«' is backspace
  ]
  open-bracket:event <- merge 0:literal/text, 91:literal/open-bracket, 0:literal/dummy, 0:literal/dummy
  replace-in-console 40:literal/open-paren, open-bracket:event
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
#?     d:address:array:event <- get console:address/deref, data:offset #? 1
#?     $print [a: ], d:address:array:event #? 1
#?     x:number <- length d:address:array:event/deref #? 1
#?     $print [b: ], x:number #? 1
    read-instruction console:address, screen:address
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .                              .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .z                             .
    .                              .
  ]
]

scenario read-instruction-cancel-string-inside-string-on-backspace [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [(a[b]«««b)]  # '(' is '[' and '«' is backspace
  ]
  open-bracket:event <- merge 0:literal/text, 91:literal/open-bracket, 0:literal/dummy, 0:literal/dummy
  replace-in-console 40:literal/open-paren, open-bracket:event
  close-bracket:event <- merge 0:literal/text, 93:literal/close-bracket, 0:literal/dummy, 0:literal/dummy
  replace-in-console 41:literal/close-paren, close-bracket:event
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain-in-color 6:literal/cyan, [
    .[ab]                          .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .                              .
    .                              .
  ]
]

scenario read-instruction-backspace-back-into-string [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [[a]«b]  # '«' is backspace
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .\\\[ab                           .
    .                              .
  ]
#?   $print [aaa] #? 1
  screen-should-contain-in-color 6:literal/cyan, [
    .\\\[ab                           .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .                              .
    .                              .
  ]
  # todo: trace sequence of events
  #   slurp-regular-characters: [
  #   slurp-regular-characters/slurp-string: a
  #   slurp-regular-characters/slurp-string: ]
  #   slurp-regular-characters/slurp-string/slurp-regular-characters: backspace
  #   slurp-regular-characters/slurp-string: b
]

scenario read-instruction-highlight-start-of-assignment [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [a <]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .a <                           .
    .                              .
  ]
  screen-should-contain-in-color 1:literal/red, [
    .  <                           .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .a                             .
    .                              .
  ]
]

scenario read-instruction-highlight-assignment [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [a <- b]
  ]
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .a <- b                        .
    .                              .
  ]
  screen-should-contain-in-color 1:literal/red, [
    .  <-                          .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .a    b                        .
    .                              .
  ]
]

scenario read-instruction-backspace-over-assignment [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [a <-«]  # '«' is backspace
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .a <                           .
    .                              .
  ]
  screen-should-contain-in-color 1:literal/red, [
    .  <                           .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .a                             .
    .                              .
  ]
]

scenario read-instruction-assignment-continues-after-backspace [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [a <-«-]  # '«' is backspace
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
#?   $print [aaa] #? 1
  run [
    read-instruction console:address, screen:address
  ]
  screen-should-contain [
    .a <-                          .
    .                              .
  ]
  screen-should-contain-in-color 1:literal/red, [
    .  <-                          .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .a                             .
    .                              .
  ]
]

scenario read-instruction-assignment-continues-after-backspace2 [
  assume-screen 30:literal/width, 5:literal/height
  assume-console [
    type [a <- ««-]  # '«' is backspace
  ]
  backspace:event <- merge 0:literal/text, 8:literal/backspace, 0:literal/dummy, 0:literal/dummy
  replace-in-console 171:literal/«, backspace:event
  run [
    read-instruction console:address, screen:address
#?     $browse-trace #? 1
  ]
  screen-should-contain [
    .a <-                          .
    .                              .
  ]
  screen-should-contain-in-color 1:literal/red, [
    .  <-                          .
    .                              .
  ]
  screen-should-contain-in-color 7:literal/white, [
    .a                             .
    .                              .
  ]
]