Mu - chessboard.mu

  1 # Chessboard program: you type in moves in algebraic notation, and it'll
  2 # display the position after each move.
  3 
  4 def main [
  5   local-scope
  6   open-console  # take control of screen, keyboard and mouse
  7   clear-screen null/screen  # non-scrolling app
  8 
  9   # The chessboard function takes keyboard and screen objects as inputs.
 10   #
 11   # In Mu it is good form (though not required) to explicitly state what
 12   # hardware a function needs.
 13   #
 14   # Here the console and screen are both null, which usually indicates real
 15   # hardware rather than a fake for testing as you'll see below.
 16   chessboard null/screen, null/console
 17 
 18   close-console  # clean up screen, keyboard and mouse
 19 ]
 20 
 21 ## But enough about Mu. Here's what it looks like to run the chessboard program.
 22 
 23 scenario print-board-and-read-move [
 24   local-scope
 25   trace-until 100/app
 26   # we'll make the screen really wide because the program currently prints out a long line
 27   assume-screen 120/width, 20/height
 28   # initialize keyboard to type in a move
 29   assume-console [
 30     type [a2-a4
 31 ]
 32   ]
 33   run [
 34     screen, console <- chessboard screen, console
 35     # icon for the cursor
 36     cursor-icon:char <- copy 9251/␣
 37     screen <- print screen, cursor-icon
 38   ]
 39   screen-should-contain [
 40   #            1         2         3         4         5         6         7         8         9         10        11
 41   #  012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789
 42     .Stupid text-mode chessboard. White pieces in uppercase; black pieces in lowercase. No checking for legal moves.         .
 43     .                                                                                                                        .
 44     .8 | r n b q k b n r                                                                                                     .
 45     .7 | p p p p p p p p                                                                                                     .
 46     .6 |                                                                                                                     .
 47     .5 |                                                                                                                     .
 48     .4 | P                                                                                                                   .
 49     .3 |                                                                                                                     .
 50     .2 |   P P P P P P P                                                                                                     .
 51     .1 | R N B Q K B N R                                                                                                     .
 52     .  +----------------                                                                                                     .
 53     .    a b c d e f g h                                                                                                     .
 54     .                                                                                                                        .
 55     .Type in your move as <from square>-<to square>. For example: 'a2-a4'. Then press <enter>.                               .
 56     .                                                                                                                        .
 57     .Hit 'q' to exit.                                                                                                        .
 58     .                                                                                                                        .
 59     .move: ␣                                                                                                                 .
 60     .                                                                                                                        .
 61     .                                                                                                                        .
 62   ]
 63 ]
 64 
 65 ## Here's how 'chessboard' is implemented.
 66 
 67 type board = &:@:&:@:char  # a 2-D array of arrays of characters
 68 
 69 def chessboard screen:&:screen, console:&:console -> screen:&:screen, console:&:console [
 70   local-scope
 71   load-inputs
 72   board:board <- initial-position
 73   # hook up stdin
 74   stdin-in:&:source:char, stdin-out:&:sink:char <- new-channel 10/capacity
 75   start-running send-keys-to-channel, console, stdin-out, screen
 76   # buffer lines in stdin
 77   buffered-stdin-in:&:source:char, buffered-stdin-out:&:sink:char <- new-channel 10/capacity
 78   start-running buffer-lines, stdin-in, buffered-stdin-out
 79   {
 80     print screen, [Stupid text-mode chessboard. White pieces in uppercase; black pieces in lowercase. No checking for legal moves.
 81 ]
 82     cursor-to-next-line screen
 83     print screen, board
 84     cursor-to-next-line screen
 85     print screen, [Type in your move as <from square>-<to square>. For example: 'a2-a4'. Then press <enter>.
 86 ]
 87     cursor-to-next-line screen
 88     print screen [Hit 'q' to exit.
 89 ]
 90     {
 91       cursor-to-next-line screen
 92       screen <- print screen, [move: ]
 93       m:&:move, quit:bool, error:bool <- read-move buffered-stdin-in, screen
 94       break-if quit, +quit
 95       buffered-stdin-in <- clear buffered-stdin-in  # cleanup after error. todo: test this?
 96       loop-if error
 97     }
 98     board <- make-move board, m
 99     screen <- clear-screen screen
100     loop
101   }
102   +quit
103 ]
104 
105 ## a board is an array of files, a file is an array of characters (squares)
106 
107 def new-board initial-position:&:@:char -> board:board [
108   local-scope
109   load-inputs
110   # assert(length(initial-position) == 64)
111   len:num <- length *initial-position
112   correct-length?:bool <- equal len, 64
113   assert correct-length?, [chessboard had incorrect size]
114   # board is an array of pointers to files; file is an array of characters
115   board <- new {(address array character): type}, 8
116   col:num <- copy 0
117   {
118     done?:bool <- equal col, 8
119     break-if done?
120     file:&:@:char <- new-file initial-position, col
121     *board <- put-index *board, col, file
122     col <- add col, 1
123     loop
124   }
125 ]
126 
127 def new-file position:&:@:char, index:num -> result:&:@:char [
128   local-scope
129   load-inputs
130   index <- multiply index, 8
131   result <- new character:type, 8
132   row:num <- copy 0
133   {
134     done?:bool <- equal row, 8
135     break-if done?
136     square:char <- index *position, index
137     *result <- put-index *result, row, square
138     row <- add row, 1
139     index <- add index, 1
140     loop
141   }
142 ]
143 
144 def print screen:&:screen, board:board -> screen:&:screen [
145   local-scope
146   load-inputs
147   row:num <- copy 7  # start printing from the top of the board
148   space:char <- copy 32/space
149   # print each row
150   {
151     done?:bool <- lesser-than row, 0
152     break-if done?
153     # print rank number as a legend
154     rank:num <- add row, 1
155     print screen, rank
156     print screen, [ | ]
157     # print each square in the row
158     col:num <- copy 0
159     {
160       done?:bool <- equal col:num, 8
161       break-if done?
162       f:&:@:char <- index *board, col
163       c:char <- index *f, row
164       bg:num <- square-color row, col
165       print screen, c, 7/white, bg
166       print screen, space
167       col <- add col, 1
168       loop
169     }
170     row <- subtract row, 1
171     cursor-to-next-line screen
172     loop
173   }
174   # print file letters as legend
175   print screen, [  +----------------]
176   cursor-to-next-line screen
177   print screen, [    a b c d e f g h]
178   cursor-to-next-line screen
179 ]
180 
181 def square-color row:num, col:num -> result:num [
182   local-scope
183   load-inputs
184   result <- copy 0/black
185   x:num <- add row, col
186   _, rem:num <- divide-with-remainder x, 2
187   return-if rem, 238
188 ]
189 
190 def initial-position -> board:board [
191   local-scope
192   # layout in memory (in raster order):
193   #   R P _ _ _ _ p r
194   #   N P _ _ _ _ p n
195   #   B P _ _ _ _ p b
196   #   Q P _ _ _ _ p q
197   #   K P _ _ _ _ p k
198   #   B P _ _ _ _ p B
199   #   N P _ _ _ _ p n
200   #   R P _ _ _ _ p r
201   initial-position:&:@:char <- new-array 82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r, 78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n, 66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b, 81/Q, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 113/q, 75/K, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 107/k, 66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b, 78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n, 82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r
202 #?       82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r,
203 #?       78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n,
204 #?       66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b, 
205 #?       81/Q, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 113/q,
206 #?       75/K, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 107/k,
207 #?       66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b,
208 #?       78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n,
209 #?       82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r
210   board <- new-board initial-position
211 ]
212 
213 scenario printing-the-board [
214   local-scope
215   board:board <- initial-position
216   assume-screen 30/width, 12/height
217   run [
218     screen <- print screen, board
219   ]
220   screen-should-contain [
221   #  012345678901234567890123456789
222     .8 | r n b q k b n r           .
223     .7 | p p p p p p p p           .
224     .6 |                           .
225     .5 |                           .
226     .4 |                           .
227     .3 |                           .
228     .2 | P P P P P P P P           .
229     .1 | R N B Q K B N R           .
230     .  +----------------           .
231     .    a b c d e f g h           .
232     .                              .
233     .                              .
234   ]
235 ]
236 
237 ## data structure: move
238 
239 container move [
240   # valid range: 0-7
241   from-file:num
242   from-rank:num
243   to-file:num
244   to-rank:num
245 ]
246 
247 # prints only error messages to screen
248 def read-move stdin:&:source:char, screen:&:screen -> result:&:move, quit?:bool, error?:bool, stdin:&:source:char, screen:&:screen [
249   local-scope
250   load-inputs
251   from-file:num, quit?:bool, error?:bool <- read-file stdin, screen
252   return-if quit?, null/dummy
253   return-if error?, null/dummy
254   # construct the move object
255   result:&:move <- new move:type
256   *result <- put *result, from-file:offset, from-file
257   from-rank:num, quit?, error? <- read-rank stdin, screen
258   return-if quit?, null/dummy
259   return-if error?, null/dummy
260   *result <- put *result, from-rank:offset, from-rank
261   error? <- expect-from-channel stdin, 45/dash, screen
262   return-if error?, null/dummy, false/quit
263   to-file:num, quit?, error? <- read-file stdin, screen
264   return-if quit?, null/dummy
265   return-if error?, null/dummy
266   *result <- put *result, to-file:offset, to-file
267   to-rank:num, quit?, error? <- read-rank stdin, screen
268   return-if quit?, null/dummy
269   return-if error?, null/dummy
270   *result <- put *result, to-rank:offset, to-rank
271   error? <- expect-from-channel stdin, 10/newline, screen
272   return-if error?, null/dummy, false/quit
273 ]
274 
275 # valid values for file: 0-7
276 def read-file stdin:&:source:char, screen:&:screen -> file:num, quit:bool, error:bool, stdin:&:source:char, screen:&:screen [
277   local-scope
278   load-inputs
279   c:char, eof?:bool, stdin <- read stdin
280   return-if eof?, 0/dummy, true/quit, false/no-error
281   q-pressed?:bool <- equal c, 81/Q
282   return-if q-pressed?, 0/dummy, true/quit, false/no-error
283   q-pressed? <- equal c, 113/q
284   return-if q-pressed?, 0/dummy, true/quit, false/no-error
285   empty-fake-keyboard?:bool <- equal c, 0/eof
286   return-if empty-fake-keyboard?, 0/dummy, true/quit, false/no-error
287   {
288     newline?:bool <- equal c, 10/newline
289     break-unless newline?
290     print screen, [that's not enough]
291     return 0/dummy, false/don't-quit, true/error
292   }
293   file:num <- subtract c, 97/a
294   # 'a' <= file <= 'h'
295   {
296     above-min:bool <- greater-or-equal file, 0
297     break-if above-min
298     print screen, [file too low: ]
299     print screen, c
300     cursor-to-next-line screen
301     return 0/dummy, false/don't-quit, true/error
302   }
303   {
304     below-max:bool <- lesser-than file, 8
305     break-if below-max
306     print screen, [file too high: ]
307     print screen, c
308     return 0/dummy, false/don't-quit, true/error
309   }
310   return file, false/don't-quit, false/no-error
311 ]
312 
313 # valid values for rank: 0-7
314 def read-rank stdin:&:source:char, screen:&:screen -> rank:num, quit?:bool, error?:bool, stdin:&:source:char, screen:&:screen [
315   local-scope
316   load-inputs
317   c:char, eof?:bool, stdin <- read stdin
318   return-if eof?, 0/dummy, true/quit, false/no-error
319   q-pressed?:bool <- equal c, 81/Q
320   return-if q-pressed?, 0/dummy, true/quit, false/no-error
321   q-pressed? <- equal c, 113/q
322   return-if q-pressed?, 0/dummy, true/quit, false/no-error
323   empty-fake-keyboard?:bool <- equal c, 0/eof
324   return-if empty-fake-keyboard?, 0/dummy, true/quit, false/no-error
325   {
326     newline?:bool <- equal c, 10  # newline
327     break-unless newline?
328     print screen, [that's not enough]
329     return 0/dummy, false/don't-quite, true/error
330   }
331   rank:num <- subtract c, 49/'1'
332   # assert'1' <= rank <= '8'
333   {
334     above-min:bool <- greater-or-equal rank, 0
335     break-if above-min
336     print screen, [rank too low: ]
337     print screen, c
338     return 0/dummy, false/don't-quite, true/error
339   }
340   {
341     below-max:bool <- lesser-or-equal rank, 7
342     break-if below-max
343     print screen, [rank too high: ]
344     print screen, c
345     return 0/dummy, false/don't-quite, true/error
346   }
347   return rank, false/don't-quite, false/no-error
348 ]
349 
350 # read a character from the given channel and check that it's what we expect
351 # return true on error
352 def expect-from-channel stdin:&:source:char, expected:char, screen:&:screen -> result:bool, stdin:&:source:char, screen:&:screen [
353   local-scope
354   load-inputs
355   c:char, eof?:bool, stdin <- read stdin
356   return-if eof? true
357   {
358     match?:bool <- equal c, expected
359     break-if match?
360     print screen, [expected character not found]
361   }
362   result <- not match?
363 ]
364 
365 scenario read-move-blocking [
366   local-scope
367   assume-screen 20/width, 2/height
368   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
369   read-move-routine:num/routine <- start-running read-move, source, screen
370   run [
371     # 'read-move' is waiting for keypress
372     wait-for-routine-to-block read-move-routine
373     read-move-state:num <- routine-state read-move-routine
374     waiting?:bool <- not-equal read-move-state, 2/discontinued
375     assert waiting?, [ 
376 F read-move-blocking: routine failed to pause after coming up (before any keys were pressed)]
377     # press 'a'
378     sink <- write sink, 97/a
379     restart read-move-routine
380     # 'read-move' still waiting for keypress
381     wait-for-routine-to-block read-move-routine
382     read-move-state <- routine-state read-move-routine
383     waiting? <- not-equal read-move-state, 2/discontinued
384     assert waiting?, [ 
385 F read-move-blocking: routine failed to pause after rank 'a']
386     # press '2'
387     sink <- write sink, 50/'2'
388     restart read-move-routine
389     # 'read-move' still waiting for keypress
390     wait-for-routine-to-block read-move-routine
391     read-move-state <- routine-state read-move-routine
392     waiting? <- not-equal read-move-state, 2/discontinued
393     assert waiting?, [ 
394 F read-move-blocking: routine failed to pause after file 'a2']
395     # press '-'
396     sink <- write sink, 45/'-'
397     restart read-move-routine
398     # 'read-move' still waiting for keypress
399     wait-for-routine-to-block read-move-routine
400     read-move-state <- routine-state read-move-routine
401     waiting? <- not-equal read-move-state, 2/discontinued
402     assert waiting?, [ 
403 F read-move-blocking: routine failed to pause after hyphen 'a2-']
404     # press 'a'
405     sink <- write sink, 97/a
406     restart read-move-routine
407     # 'read-move' still waiting for keypress
408     wait-for-routine-to-block read-move-routine
409     read-move-state <- routine-state read-move-routine
410     waiting? <- not-equal read-move-state, 2/discontinued
411     assert waiting?, [ 
412 F read-move-blocking: routine failed to pause after rank 'a2-a']
413     # press '4'
414     sink <- write sink, 52/'4'
415     restart read-move-routine
416     # 'read-move' still waiting for keypress
417     wait-for-routine-to-block read-move-routine
418     read-move-state <- routine-state read-move-routine
419     waiting? <- not-equal read-move-state, 2/discontinued
420     assert waiting?, [ 
421 F read-move-blocking: routine failed to pause after file 'a2-a4']
422     # press 'newline'
423     sink <- write sink, 10  # newline
424     restart read-move-routine
425     # 'read-move' now completes
426     wait-for-routine-to-block read-move-routine
427     read-move-state <- routine-state read-move-routine
428     completed?:bool <- equal read-move-state, 1/completed
429     assert completed?, [ 
430 F read-move-blocking: routine failed to terminate on newline]
431     trace 1, [test], [reached end]
432   ]
433   trace-should-contain [
434     test: reached end
435   ]
436 ]
437 
438 scenario read-move-quit [
439   local-scope
440   assume-screen 20/width, 2/height
441   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
442   read-move-routine:num <- start-running read-move, source, screen
443   run [
444     # 'read-move' is waiting for keypress
445     wait-for-routine-to-block read-move-routine
446     read-move-state:num <- routine-state read-move-routine
447     waiting?:bool <- not-equal read-move-state, 2/discontinued
448     assert waiting?, [ 
449 F read-move-quit: routine failed to pause after coming up (before any keys were pressed)]
450     # press 'q'
451     sink <- write sink, 113/q
452     restart read-move-routine
453     # 'read-move' completes
454     wait-for-routine-to-block read-move-routine
455     read-move-state <- routine-state read-move-routine
456     completed?:bool <- equal read-move-state, 1/completed
457     assert completed?, [ 
458 F read-move-quit: routine failed to terminate on 'q']
459     trace 1, [test], [reached end]
460   ]
461   trace-should-contain [
462     test: reached end
463   ]
464 ]
465 
466 scenario read-move-illegal-file [
467   local-scope
468   assume-screen 20/width, 2/height
469   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
470   read-move-routine:num <- start-running read-move, source, screen
471   run [
472     # 'read-move' is waiting for keypress
473     wait-for-routine-to-block read-move-routine
474     read-move-state:num <- routine-state read-move-routine
475     waiting?:bool <- not-equal read-move-state, 2/discontinued
476     assert waiting?, [ 
477 F read-move-illegal-file: routine failed to pause after coming up (before any keys were pressed)]
478     sink <- write sink, 50/'2'
479     restart read-move-routine
480     wait-for-routine-to-block read-move-routine
481   ]
482   screen-should-contain [
483     .file too low: 2     .
484     .                    .
485   ]
486 ]
487 
488 scenario read-move-illegal-rank [
489   local-scope
490   assume-screen 20/width, 2/height
491   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
492   read-move-routine:num <- start-running read-move, source, screen
493   run [
494     # 'read-move' is waiting for keypress
495     wait-for-routine-to-block read-move-routine
496     read-move-state:num <- routine-state read-move-routine
497     waiting?:bool <- not-equal read-move-state, 2/discontinued
498     assert waiting?, [ 
499 F read-move-illegal-rank: routine failed to pause after coming up (before any keys were pressed)]
500     sink <- write sink, 97/a
501     sink <- write sink, 97/a
502     restart read-move-routine
503     wait-for-routine-to-block read-move-routine
504   ]
505   screen-should-contain [
506     .rank too high: a    .
507     .                    .
508   ]
509 ]
510 
511 scenario read-move-empty [
512   local-scope
513   assume-screen 20/width, 2/height
514   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
515   read-move-routine:num <- start-running read-move, source, screen
516   run [
517     # 'read-move' is waiting for keypress
518     wait-for-routine-to-block read-move-routine
519     read-move-state:num <- routine-state read-move-routine
520     waiting?:bool <- not-equal read-move-state, 2/discontinued
521     assert waiting?, [ 
522 F read-move-empty: routine failed to pause after coming up (before any keys were pressed)]
523     sink <- write sink, 10/newline
524     sink <- write sink, 97/a
525     restart read-move-routine
526     wait-for-routine-to-block read-move-routine
527   ]
528   screen-should-contain [
529     .that's not enough   .
530     .                    .
531   ]
532 ]
533 
534 def make-move board:board, m:&:move -> board:board [
535   local-scope
536   load-inputs
537   from-file:num <- get *m, from-file:offset
538   from-rank:num <- get *m, from-rank:offset
539   to-file:num <- get *m, to-file:offset
540   to-rank:num <- get *m, to-rank:offset
541   from-f:&:@:char <- index *board, from-file
542   to-f:&:@:char <- index *board, to-file
543   src:char/square <- index *from-f, from-rank
544   *to-f <- put-index *to-f, to-rank, src
545   *from-f <- put-index *from-f, from-rank, 32/space
546 ]
547 
548 scenario making-a-move [
549   local-scope
550   assume-screen 30/width, 12/height
551   board:board <- initial-position
552   move:&:move <- new move:type
553   *move <- merge 6/g, 1/'2', 6/g, 3/'4'
554   run [
555     board <- make-move board, move
556     screen <- print screen, board
557   ]
558   screen-should-contain [
559   #  012345678901234567890123456789
560     .8 | r n b q k b n r           .
561     .7 | p p p p p p p p           .
562     .6 |                           .
563     .5 |                           .
564     .4 |             P             .
565     .3 |                           .
566     .2 | P P P P P P   P           .
567     .1 | R N B Q K B N R           .
568     .  +----------------           .
569     .    a b c d e f g h           .
570     .                              .
571   ]
572 ]