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 
  8   # The chessboard function takes keyboard and screen objects as 'ingredients'.
  9   #
 10   # In Mu it is good form (though not required) to explicitly state what
 11   # hardware a function needs.
 12   #
 13   # Here the console and screen are both 0, which usually indicates real
 14   # hardware rather than a fake for testing as you'll see below.
 15   chessboard 0/screen, 0/console
 16 
 17   close-console  # clean up screen, keyboard and mouse
 18 ]
 19 
 20 ## But enough about Mu. Here's what it looks like to run the chessboard program.
 21 
 22 scenario print-board-and-read-move [
 23   local-scope
 24   trace-until 100/app
 25   # we'll make the screen really wide because the program currently prints out a long line
 26   assume-screen 120/width, 20/height
 27   # initialize keyboard to type in a move
 28   assume-console [
 29     type [a2-a4
 30 ]
 31   ]
 32   run [
 33     screen:&:screen, console:&:console <- chessboard screen:&:screen, console:&:console
 34     # icon for the cursor
 35     cursor-icon:char <- copy 9251/␣
 36     screen <- print screen, cursor-icon
 37   ]
 38   screen-should-contain [
 39   #            1         2         3         4         5         6         7         8         9         10        11
 40   #  012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789
 41     .Stupid text-mode chessboard. White pieces in uppercase; black pieces in lowercase. No checking for legal moves.         .
 42     .                                                                                                                        .
 43     .8 | r n b q k b n r                                                                                                     .
 44     .7 | p p p p p p p p                                                                                                     .
 45     .6 |                                                                                                                     .
 46     .5 |                                                                                                                     .
 47     .4 | P                                                                                                                   .
 48     .3 |                                                                                                                     .
 49     .2 |   P P P P P P P                                                                                                     .
 50     .1 | R N B Q K B N R                                                                                                     .
 51     .  +----------------                                                                                                     .
 52     .    a b c d e f g h                                                                                                     .
 53     .                                                                                                                        .
 54     .Type in your move as <from square>-<to square>. For example: 'a2-a4'. Then press <enter>.                               .
 55     .                                                                                                                        .
 56     .Hit 'q' to exit.                                                                                                        .
 57     .                                                                                                                        .
 58     .move: ␣                                                                                                                 .
 59     .                                                                                                                        .
 60     .                                                                                                                        .
 61   ]
 62 ]
 63 
 64 ## Here's how 'chessboard' is implemented.
 65 
 66 type board = &:@:&:@:char  # a 2-D array of arrays of characters
 67 
 68 def chessboard screen:&:screen, console:&:console -> screen:&:screen, console:&:console [
 69   local-scope
 70   load-ingredients
 71   board:board <- initial-position
 72   # hook up stdin
 73   stdin-in:&:source:char, stdin-out:&:sink:char <- new-channel 10/capacity
 74   start-running send-keys-to-channel, console, stdin-out, screen
 75   # buffer lines in stdin
 76   buffered-stdin-in:&:source:char, buffered-stdin-out:&:sink:char <- new-channel 10/capacity
 77   start-running buffer-lines, stdin-in, buffered-stdin-out
 78   {
 79     print screen, [Stupid text-mode chessboard. White pieces in uppercase; black pieces in lowercase. No checking for legal moves.
 80 ]
 81     cursor-to-next-line screen
 82     print-board screen, board
 83     cursor-to-next-line screen
 84     print screen, [Type in your move as <from square>-<to square>. For example: 'a2-a4'. Then press <enter>.
 85 ]
 86     cursor-to-next-line screen
 87     print screen [Hit 'q' to exit.
 88 ]
 89     {
 90       cursor-to-next-line screen
 91       screen <- print screen, [move: ]
 92       m:&:move, quit:bool, error:bool <- read-move buffered-stdin-in, screen
 93       break-if quit, +quit
 94       buffered-stdin-in <- clear buffered-stdin-in  # cleanup after error. todo: test this?
 95       loop-if error
 96     }
 97     board <- make-move board, m
 98     screen <- clear-screen screen
 99     loop
100   }
101   +quit
102 ]
103 
104 ## a board is an array of files, a file is an array of characters (squares)
105 
106 def new-board initial-position:&:@:char -> board:board [
107   local-scope
108   load-ingredients
109   # assert(length(initial-position) == 64)
110   len:num <- length *initial-position
111   correct-length?:bool <- equal len, 64
112   assert correct-length?, [chessboard had incorrect size]
113   # board is an array of pointers to files; file is an array of characters
114   board <- new {(address array character): type}, 8
115   col:num <- copy 0
116   {
117     done?:bool <- equal col, 8
118     break-if done?
119     file:&:@:char <- new-file initial-position, col
120     *board <- put-index *board, col, file
121     col <- add col, 1
122     loop
123   }
124 ]
125 
126 def new-file position:&:@:char, index:num -> result:&:@:char [
127   local-scope
128   load-ingredients
129   index <- multiply index, 8
130   result <- new character:type, 8
131   row:num <- copy 0
132   {
133     done?:bool <- equal row, 8
134     break-if done?
135     square:char <- index *position, index
136     *result <- put-index *result, row, square
137     row <- add row, 1
138     index <- add index, 1
139     loop
140   }
141 ]
142 
143 def print-board screen:&:screen, board:board -> screen:&:screen [
144   local-scope
145   load-ingredients
146   row:num <- copy 7  # start printing from the top of the board
147   space:char <- copy 32/space
148   # print each row
149   {
150     done?:bool <- lesser-than row, 0
151     break-if done?
152     # print rank number as a legend
153     rank:num <- add row, 1
154     print-integer screen, rank
155     print screen, [ | ]
156     # print each square in the row
157     col:num <- copy 0
158     {
159       done?:bool <- equal col:num, 8
160       break-if done?:bool
161       f:&:@:char <- index *board, col
162       c:char <- index *f, row
163       print screen, c
164       print screen, space
165       col <- add col, 1
166       loop
167     }
168     row <- subtract row, 1
169     cursor-to-next-line screen
170     loop
171   }
172   # print file letters as legend
173   print screen, [  +----------------]
174   cursor-to-next-line screen
175   print screen, [    a b c d e f g h]
176   cursor-to-next-line screen
177 ]
178 
179 def initial-position -> board:board [
180   local-scope
181   # layout in memory (in raster order):
182   #   R P _ _ _ _ p r
183   #   N P _ _ _ _ p n
184   #   B P _ _ _ _ p b
185   #   Q P _ _ _ _ p q
186   #   K P _ _ _ _ p k
187   #   B P _ _ _ _ p B
188   #   N P _ _ _ _ p n
189   #   R P _ _ _ _ p r
190   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
191 #?       82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r,
192 #?       78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n,
193 #?       66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b, 
194 #?       81/Q, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 113/q,
195 #?       75/K, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 107/k,
196 #?       66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b,
197 #?       78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n,
198 #?       82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r
199   board <- new-board initial-position
200 ]
201 
202 scenario printing-the-board [
203   local-scope
204   board:board <- initial-position
205   assume-screen 30/width, 12/height
206   run [
207     screen:&:screen <- print-board screen:&:screen, board
208   ]
209   screen-should-contain [
210   #  012345678901234567890123456789
211     .8 | r n b q k b n r           .
212     .7 | p p p p p p p p           .
213     .6 |                           .
214     .5 |                           .
215     .4 |                           .
216     .3 |                           .
217     .2 | P P P P P P P P           .
218     .1 | R N B Q K B N R           .
219     .  +----------------           .
220     .    a b c d e f g h           .
221     .                              .
222     .                              .
223   ]
224 ]
225 
226 ## data structure: move
227 
228 container move [
229   # valid range: 0-7
230   from-file:num
231   from-rank:num
232   to-file:num
233   to-rank:num
234 ]
235 
236 # prints only error messages to screen
237 def read-move stdin:&:source:char, screen:&:screen -> result:&:move, quit?:bool, error?:bool, stdin:&:source:char, screen:&:screen [
238   local-scope
239   load-ingredients
240   from-file:num, quit?:bool, error?:bool <- read-file stdin, screen
241   return-if quit?, 0/dummy
242   return-if error?, 0/dummy
243   # construct the move object
244   result:&:move <- new move:type
245   *result <- put *result, from-file:offset, from-file
246   from-rank:num, quit?, error? <- read-rank stdin, screen
247   return-if quit?, 0/dummy
248   return-if error?, 0/dummy
249   *result <- put *result, from-rank:offset, from-rank
250   error? <- expect-from-channel stdin, 45/dash, screen
251   return-if error?, 0/dummy, 0/quit
252   to-file:num, quit?, error? <- read-file stdin, screen
253   return-if quit?:bool, 0/dummy
254   return-if error?:bool, 0/dummy
255   *result <- put *result, to-file:offset, to-file
256   to-rank:num, quit?, error? <- read-rank stdin, screen
257   return-if quit?, 0/dummy
258   return-if error?, 0/dummy
259   *result <- put *result, to-rank:offset, to-rank
260   error? <- expect-from-channel stdin, 10/newline, screen
261   return-if error?, 0/dummy, 0/quit
262 ]
263 
264 # valid values for file: 0-7
265 def read-file stdin:&:source:char, screen:&:screen -> file:num, quit:bool, error:bool, stdin:&:source:char, screen:&:screen [
266   local-scope
267   load-ingredients
268   c:char, eof?:bool, stdin <- read stdin
269   return-if eof?, 0/dummy, 1/quit, 0/error
270   {
271     q-pressed?:bool <- equal c, 81/Q
272     break-unless q-pressed?
273     return 0/dummy, 1/quit, 0/error
274   }
275   {
276     q-pressed? <- equal c, 113/q
277     break-unless q-pressed?
278     return 0/dummy, 1/quit, 0/error
279   }
280   {
281     empty-fake-keyboard?:bool <- equal c, 0/eof
282     break-unless empty-fake-keyboard?
283     return 0/dummy, 1/quit, 0/error
284   }
285   {
286     newline?:bool <- equal c, 10/newline
287     break-unless newline?
288     print screen, [that's not enough]
289     return 0/dummy, 0/quit, 1/error
290   }
291   file:num <- subtract c, 97/a
292   # 'a' <= file <= 'h'
293   {
294     above-min:bool <- greater-or-equal file, 0
295     break-if above-min
296     print screen, [file too low: ]
297     print screen, c
298     cursor-to-next-line screen
299     return 0/dummy, 0/quit, 1/error
300   }
301   {
302     below-max:bool <- lesser-than file, 8
303     break-if below-max
304     print screen, [file too high: ]
305     print screen, c
306     return 0/dummy, 0/quit, 1/error
307   }
308   return file, 0/quit, 0/error
309 ]
310 
311 # valid values for rank: 0-7
312 def read-rank stdin:&:source:char, screen:&:screen -> rank:num, quit?:bool, error?:bool, stdin:&:source:char, screen:&:screen [
313   local-scope
314   load-ingredients
315   c:char, eof?:bool, stdin <- read stdin
316   return-if eof?, 0/dummy, 1/quit, 0/error
317   {
318     q-pressed?:bool <- equal c, 8/Q
319     break-unless q-pressed?
320     return 0/dummy, 1/quit, 0/error
321   }
322   {
323     q-pressed? <- equal c, 113/q
324     break-unless q-pressed?
325     return 0/dummy, 1/quit, 0/error
326   }
327   {
328     newline?:bool <- equal c, 10  # newline
329     break-unless newline?
330     print screen, [that's not enough]
331     return 0/dummy, 0/quit, 1/error
332   }
333   rank:num <- subtract c, 49/'1'
334   # assert'1' <= rank <= '8'
335   {
336     above-min:bool <- greater-or-equal rank, 0
337     break-if above-min
338     print screen, [rank too low: ]
339     print screen, c
340     return 0/dummy, 0/quit, 1/error
341   }
342   {
343     below-max:bool <- lesser-or-equal rank, 7
344     break-if below-max
345     print screen, [rank too high: ]
346     print screen, c
347     return 0/dummy, 0/quit, 1/error
348   }
349   return rank, 0/quit, 0/error
350 ]
351 
352 # read a character from the given channel and check that it's what we expect
353 # return true on error
354 def expect-from-channel stdin:&:source:char, expected:char, screen:&:screen -> result:bool, stdin:&:source:char, screen:&:screen [
355   local-scope
356   load-ingredients
357   c:char, eof?:bool, stdin <- read stdin
358   return-if eof? 1/true
359   {
360     match?:bool <- equal c, expected
361     break-if match?
362     print screen, [expected character not found]
363   }
364   result <- not match?
365 ]
366 
367 scenario read-move-blocking [
368   local-scope
369   assume-screen 20/width, 2/height
370   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
371   read-move-routine:num/routine <- start-running read-move, source, screen:&:screen
372   run [
373     # 'read-move' is waiting for input
374     wait-for-routine-to-block read-move-routine
375     read-move-state:num <- routine-state read-move-routine
376     waiting?:bool <- not-equal read-move-state, 2/discontinued
377     assert waiting?, [ 
378 F read-move-blocking: routine failed to pause after coming up (before any keys were pressed)]
379     # press 'a'
380     sink <- write sink, 97/a
381     restart read-move-routine
382     # 'read-move' still waiting for input
383     wait-for-routine-to-block read-move-routine
384     read-move-state <- routine-state read-move-routine
385     waiting? <- not-equal read-move-state, 2/discontinued
386     assert waiting?, [ 
387 F read-move-blocking: routine failed to pause after rank 'a']
388     # press '2'
389     sink <- write sink, 50/'2'
390     restart read-move-routine
391     # 'read-move' still waiting for input
392     wait-for-routine-to-block read-move-routine
393     read-move-state <- routine-state read-move-routine
394     waiting? <- not-equal read-move-state, 2/discontinued
395     assert waiting?, [ 
396 F read-move-blocking: routine failed to pause after file 'a2']
397     # press '-'
398     sink <- write sink, 45/'-'
399     restart read-move-routine
400     # 'read-move' still waiting for input
401     wait-for-routine-to-block read-move-routine
402     read-move-state <- routine-state read-move-routine
403     waiting? <- not-equal read-move-state, 2/discontinued
404     assert waiting?, [ 
405 F read-move-blocking: routine failed to pause after hyphen 'a2-']
406     # press 'a'
407     sink <- write sink, 97/a
408     restart read-move-routine
409     # 'read-move' still waiting for input
410     wait-for-routine-to-block read-move-routine
411     read-move-state <- routine-state read-move-routine
412     waiting? <- not-equal read-move-state, 2/discontinued
413     assert waiting?, [ 
414 F read-move-blocking: routine failed to pause after rank 'a2-a']
415     # press '4'
416     sink <- write sink, 52/'4'
417     restart read-move-routine
418     # 'read-move' still waiting for input
419     wait-for-routine-to-block read-move-routine
420     read-move-state <- routine-state read-move-routine
421     waiting? <- not-equal read-move-state, 2/discontinued
422     assert waiting?, [ 
423 F read-move-blocking: routine failed to pause after file 'a2-a4']
424     # press 'newline'
425     sink <- write sink, 10  # newline
426     restart read-move-routine
427     # 'read-move' now completes
428     wait-for-routine-to-block read-move-routine
429     read-move-state <- routine-state read-move-routine
430     completed?:bool <- equal read-move-state, 1/completed
431     assert completed?, [ 
432 F read-move-blocking: routine failed to terminate on newline]
433     trace 1, [test], [reached end]
434   ]
435   trace-should-contain [
436     test: reached end
437   ]
438 ]
439 
440 scenario read-move-quit [
441   local-scope
442   assume-screen 20/width, 2/height
443   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
444   read-move-routine:num <- start-running read-move, source, screen:&:screen
445   run [
446     # 'read-move' is waiting for input
447     wait-for-routine-to-block read-move-routine
448     read-move-state:num <- routine-state read-move-routine
449     waiting?:bool <- not-equal read-move-state, 2/discontinued
450     assert waiting?, [ 
451 F read-move-quit: routine failed to pause after coming up (before any keys were pressed)]
452     # press 'q'
453     sink <- write sink, 113/q
454     restart read-move-routine
455     # 'read-move' completes
456     wait-for-routine-to-block read-move-routine
457     read-move-state <- routine-state read-move-routine
458     completed?:bool <- equal read-move-state, 1/completed
459     assert completed?, [ 
460 F read-move-quit: routine failed to terminate on 'q']
461     trace 1, [test], [reached end]
462   ]
463   trace-should-contain [
464     test: reached end
465   ]
466 ]
467 
468 scenario read-move-illegal-file [
469   local-scope
470   assume-screen 20/width, 2/height
471   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
472   read-move-routine:num <- start-running read-move, source, screen:&:screen
473   run [
474     # 'read-move' is waiting for input
475     wait-for-routine-to-block read-move-routine
476     read-move-state:num <- routine-state read-move-routine
477     waiting?:bool <- not-equal read-move-state, 2/discontinued
478     assert waiting?, [ 
479 F read-move-illegal-file: routine failed to pause after coming up (before any keys were pressed)]
480     sink <- write sink, 50/'2'
481     restart read-move-routine
482     wait-for-routine-to-block read-move-routine
483   ]
484   screen-should-contain [
485     .file too low: 2     .
486     .                    .
487   ]
488 ]
489 
490 scenario read-move-illegal-rank [
491   local-scope
492   assume-screen 20/width, 2/height
493   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
494   read-move-routine:num <- start-running read-move, source, screen:&:screen
495   run [
496     # 'read-move' is waiting for input
497     wait-for-routine-to-block read-move-routine
498     read-move-state:num <- routine-state read-move-routine
499     waiting?:bool <- not-equal read-move-state, 2/discontinued
500     assert waiting?, [ 
501 F read-move-illegal-rank: routine failed to pause after coming up (before any keys were pressed)]
502     sink <- write sink, 97/a
503     sink <- write sink, 97/a
504     restart read-move-routine
505     wait-for-routine-to-block read-move-routine
506   ]
507   screen-should-contain [
508     .rank too high: a    .
509     .                    .
510   ]
511 ]
512 
513 scenario read-move-empty [
514   local-scope
515   assume-screen 20/width, 2/height
516   source:&:source:char, sink:&:sink:char <- new-channel 2/capacity
517   read-move-routine:num <- start-running read-move, source, screen:&:screen
518   run [
519     # 'read-move' is waiting for input
520     wait-for-routine-to-block read-move-routine
521     read-move-state:num <- routine-state read-move-routine
522     waiting?:bool <- not-equal read-move-state, 2/discontinued
523     assert waiting?, [ 
524 F read-move-empty: routine failed to pause after coming up (before any keys were pressed)]
525     sink <- write sink, 10/newline
526     sink <- write sink, 97/a
527     restart read-move-routine
528     wait-for-routine-to-block read-move-routine
529   ]
530   screen-should-contain [
531     .that's not enough   .
532     .                    .
533   ]
534 ]
535 
536 def make-move board:board, m:&:move -> board:board [
537   local-scope
538   load-ingredients
539   from-file:num <- get *m, from-file:offset
540   from-rank:num <- get *m, from-rank:offset
541   to-file:num <- get *m, to-file:offset
542   to-rank:num <- get *m, to-rank:offset
543   from-f:&:@:char <- index *board, from-file
544   to-f:&:@:char <- index *board, to-file
545   src:char/square <- index *from-f, from-rank
546   *to-f <- put-index *to-f, to-rank, src
547   *from-f <- put-index *from-f, from-rank, 32/space
548 ]
549 
550 scenario making-a-move [
551   local-scope
552   assume-screen 30/width, 12/height
553   board:board <- initial-position
554   move:&:move <- new move:type
555   *move <- merge 6/g, 1/'2', 6/g, 3/'4'
556   run [
557     board <- make-move board, move
558     screen:&:screen <- print-board screen:&:screen, board
559   ]
560   screen-should-contain [
561   #  012345678901234567890123456789
562     .8 | r n b q k b n r           .
563     .7 | p p p p p p p p           .
564     .6 |                           .
565     .5 |                           .
566     .4 |             P             .
567     .3 |                           .
568     .2 | P P P P P P   P           .
569     .1 | R N B Q K B N R           .
570     .  +----------------           .
571     .    a b c d e f g h           .
572     .                              .
573   ]
574 ]