1 ## putting the environment together out of editors
  2 #
  3 # Consists of one editor on the left for recipes and one on the right for the
  4 # sandbox.
  5 
  6 def! main [
  7   local-scope
  8   open-console
  9   env:&:environment <- new-programming-environment 0/filesystem, 0/screen
 10   render-all 0/screen, env, render
 11   event-loop 0/screen, 0/console, env, 0/filesystem
 12   # never gets here
 13 ]
 14 
 15 container environment [
 16   recipes:&:editor
 17   current-sandbox:&:editor
 18   sandbox-in-focus?:bool  # false => cursor in recipes; true => cursor in current-sandbox
 19 ]
 20 
 21 def new-programming-environment resources:&:resources, screen:&:screen, test-sandbox-editor-contents:text -> result:&:environment [
 22   local-scope
 23   load-ingredients
 24   width:num <- screen-width screen
 25   result <- new environment:type
 26   # recipe editor on the left
 27   initial-recipe-contents:text <- slurp resources, [lesson/recipes.mu]  # ignore errors
 28   divider:num, _ <- divide-with-remainder width, 2
 29   recipes:&:editor <- new-editor initial-recipe-contents, 0/left, divider/right
 30   # sandbox editor on the right
 31   sandbox-left:num <- add divider, 1
 32   current-sandbox:&:editor <- new-editor test-sandbox-editor-contents, sandbox-left, width/right
 33   *result <- put *result, recipes:offset, recipes
 34   *result <- put *result, current-sandbox:offset, current-sandbox
 35   *result <- put *result, sandbox-in-focus?:offset, 0/false
 36   <programming-environment-initialization>
 37 ]
 38 
 39 def event-loop screen:&:screen, console:&:console, env:&:environment, resources:&:resources -> screen:&:screen, console:&:console, env:&:environment, resources:&:resources [
 40   local-scope
 41   load-ingredients
 42   recipes:&:editor <- get *env, recipes:offset
 43   current-sandbox:&:editor <- get *env, current-sandbox:offset
 44   sandbox-in-focus?:bool <- get *env, sandbox-in-focus?:offset
 45   # if we fall behind we'll stop updating the screen, but then we have to
 46   # render the entire screen when we catch up.
 47   # todo: test this
 48   render-all-on-no-more-events?:bool <- copy 0/false
 49   {
 50   ¦ # looping over each (keyboard or touch) event as it occurs
 51   ¦ +next-event
 52   ¦ e:event, found?:bool, quit?:bool, console <- read-event console
 53   ¦ loop-unless found?
 54   ¦ break-if quit?  # only in tests
 55   ¦ trace 10, [app], [next-event]
 56   ¦ <handle-event>
 57   ¦ # check for global events that will trigger regardless of which editor has focus
 58   ¦ {
 59   ¦ ¦ k:num, is-keycode?:bool <- maybe-convert e:event, keycode:variant
 60   ¦ ¦ break-unless is-keycode?
 61   ¦ ¦ <global-keypress>
 62   ¦ }
 63   ¦ {
 64   ¦ ¦ c:char, is-unicode?:bool <- maybe-convert e:event, text:variant
 65   ¦ ¦ break-unless is-unicode?
 66   ¦ ¦ <global-type>
 67   ¦ }
 68   ¦ # 'touch' event - send to both sides, see what picks it up
 69   ¦ {
 70   ¦ ¦ t:touch-event, is-touch?:bool <- maybe-convert e:event, touch:variant
 71   ¦ ¦ break-unless is-touch?
 72   ¦ ¦ # ignore all but 'left-click' events for now
 73   ¦ ¦ # todo: test this
 74   ¦ ¦ touch-type:num <- get t, type:offset
 75   ¦ ¦ is-left-click?:bool <- equal touch-type, 65513/mouse-left
 76   ¦ ¦ loop-unless is-left-click?, +next-event
 77   ¦ ¦ click-row:num <- get t, row:offset
 78   ¦ ¦ click-column:num <- get t, column:offset
 79   ¦ ¦ # later exceptions for non-editor touches will go here
 80   ¦ ¦ <global-touch>
 81   ¦ ¦ # send to both editors
 82   ¦ ¦ _ <- move-cursor-in-editor screen, recipes, t
 83   ¦ ¦ sandbox-in-focus?:bool <- move-cursor-in-editor screen, current-sandbox, t
 84   ¦ ¦ *env <- put *env, sandbox-in-focus?:offset, sandbox-in-focus?
 85   ¦ ¦ screen <- update-cursor screen, recipes, current-sandbox, sandbox-in-focus?, env
 86   ¦ ¦ loop +next-event
 87   ¦ }
 88   ¦ # 'resize' event - redraw editor
 89   ¦ # todo: test this after supporting resize in assume-console
 90   ¦ {
 91   ¦ ¦ r:resize-event, is-resize?:bool <- maybe-convert e:event, resize:variant
 92   ¦ ¦ break-unless is-resize?
 93   ¦ ¦ env, screen <- resize screen, env
 94   ¦ ¦ screen <- render-all screen, env, render-without-moving-cursor
 95   ¦ ¦ loop +next-event
 96   ¦ }
 97   ¦ # if it's not global and not a touch event, send to appropriate editor
 98   ¦ {
 99   ¦ ¦ sandbox-in-focus?:bool <- get *env, sandbox-in-focus?:offset
100   ¦ ¦ {
101   ¦ ¦ ¦ break-if sandbox-in-focus?
102   ¦ ¦ ¦ render?:bool <- handle-keyboard-event screen, recipes, e:event
103   ¦ ¦ ¦ # refresh screen only if no more events
104   ¦ ¦ ¦ # if there are more events to process, wait for them to clear up, then make sure you render-all afterward.
105   ¦ ¦ ¦ more-events?:bool <- has-more-events? console
106   ¦ ¦ ¦ {
107   ¦ ¦ ¦ ¦ break-unless more-events?
108   ¦ ¦ ¦ ¦ render-all-on-no-more-events? <- copy 1/true  # no rendering now, full rendering on some future event
109   ¦ ¦ ¦ ¦ jump +finish-event
110   ¦ ¦ ¦ }
111   ¦ ¦ ¦ {
112   ¦ ¦ ¦ ¦ break-if more-events?
113   ¦ ¦ ¦ ¦ {
114   ¦ ¦ ¦ ¦ ¦ break-unless render-all-on-no-more-events?
115   ¦ ¦ ¦ ¦ ¦ # no more events, and we have to force render
116   ¦ ¦ ¦ ¦ ¦ screen <- render-all screen, env, render
117   ¦ ¦ ¦ ¦ ¦ render-all-on-no-more-events? <- copy 0/false
118   ¦ ¦ ¦ ¦ ¦ jump +finish-event
119   ¦ ¦ ¦ ¦ }
120   ¦ ¦ ¦ ¦ # no more events, no force render
121   ¦ ¦ ¦ ¦ {
122   ¦ ¦ ¦ ¦ ¦ break-unless render?
123   ¦ ¦ ¦ ¦ ¦ screen <- render-recipes screen, env, render
124   ¦ ¦ ¦ ¦ ¦ jump +finish-event
125   ¦ ¦ ¦ ¦ }
126   ¦ ¦ ¦ }
127   ¦ ¦ }
128   ¦ ¦ {
129   ¦ ¦ ¦ break-unless sandbox-in-focus?
130   ¦ ¦ ¦ render?:bool <- handle-keyboard-event screen, current-sandbox, e:event
131   ¦ ¦ ¦ # refresh screen only if no more events
132   ¦ ¦ ¦ # if there are more events to process, wait for them to clear up, then make sure you render-all afterward.
133   ¦ ¦ ¦ more-events?:bool <- has-more-events? console
134   ¦ ¦ ¦ {
135   ¦ ¦ ¦ ¦ break-unless more-events?
136   ¦ ¦ ¦ ¦ render-all-on-no-more-events? <- copy 1/true  # no rendering now, full rendering on some future event
137   ¦ ¦ ¦ ¦ jump +finish-event
138   ¦ ¦ ¦ }
139   ¦ ¦ ¦ {
140   ¦ ¦ ¦ ¦ break-if more-events?
141   ¦ ¦ ¦ ¦ {
142   ¦ ¦ ¦ ¦ ¦ break-unless render-all-on-no-more-events?
143   ¦ ¦ ¦ ¦ ¦ # no more events, and we have to force render
144   ¦ ¦ ¦ ¦ ¦ screen <- render-all screen, env, render
145   ¦ ¦ ¦ ¦ ¦ render-all-on-no-more-events? <- copy 0/false
146   ¦ ¦ ¦ ¦ ¦ jump +finish-event
147   ¦ ¦ ¦ ¦ }
148   ¦ ¦ ¦ ¦ # no more events, no force render
149   ¦ ¦ ¦ ¦ {
150   ¦ ¦ ¦ ¦ ¦ break-unless render?
151   ¦ ¦ ¦ ¦ ¦ screen <- render-sandbox-side screen, env, render
152   ¦ ¦ ¦ ¦ ¦ jump +finish-event
153   ¦ ¦ ¦ ¦ }
154   ¦ ¦ ¦ }
155   ¦ ¦ }
156   ¦ ¦ +finish-event
157   ¦ ¦ screen <- update-cursor screen, recipes, current-sandbox, sandbox-in-focus?, env
158   ¦ }
159   ¦ loop
160   }
161 ]
162 
163 def resize screen:&:screen, env:&:environment -> env:&:environment, screen:&:screen [
164   local-scope
165   load-ingredients
166   clear-screen screen  # update screen dimensions
167   width:num <- screen-width screen
168   divider:num, _ <- divide-with-remainder width, 2
169   # update recipe editor
170   recipes:&:editor <- get *env, recipes:offset
171   right:num <- subtract divider, 1
172   *recipes <- put *recipes, right:offset, right
173   # reset cursor (later we'll try to preserve its position)
174   *recipes <- put *recipes, cursor-row:offset, 1
175   *recipes <- put *recipes, cursor-column:offset, 0
176   # update sandbox editor
177   current-sandbox:&:editor <- get *env, current-sandbox:offset
178   left:num <- add divider, 1
179   *current-sandbox <- put *current-sandbox, left:offset, left
180   right:num <- subtract width, 1
181   *current-sandbox <- put *current-sandbox, right:offset, right
182   # reset cursor (later we'll try to preserve its position)
183   *current-sandbox <- put *current-sandbox, cursor-row:offset, 1
184   *current-sandbox <- put *current-sandbox, cursor-column:offset, left
185 ]
186 
187 # Variant of 'render' that updates cursor-row and cursor-column based on
188 # before-cursor (rather than the other way around). If before-cursor moves
189 # off-screen, it resets cursor-row and cursor-column.
190 def render-without-moving-cursor screen:&:screen, editor:&:editor -> last-row:num, last-column:num, screen:&:screen, editor:&:editor [
191   local-scope
192   load-ingredients
193   return-unless editor, 1/top, 0/left
194   left:num <- get *editor, left:offset
195   screen-height:num <- screen-height screen
196   right:num <- get *editor, right:offset
197   curr:&:duplex-list:char <- get *editor, top-of-screen:offset
198   prev:&:duplex-list:char <- copy curr  # just in case curr becomes null and we can't compute prev
199   curr <- next curr
200   color:num <- copy 7/white
201   row:num <- copy 1/top
202   column:num <- copy left
203   # save before-cursor
204   old-before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
205   # initialze cursor-row/cursor-column/before-cursor to the top of the screen
206   # by default
207   *editor <- put *editor, cursor-row:offset, row
208   *editor <- put *editor, cursor-column:offset, column
209   top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
210   *editor <- put *editor, before-cursor:offset, top-of-screen
211   screen <- move-cursor screen, row, column
212   {
213   ¦ +next-character
214   ¦ break-unless curr
215   ¦ off-screen?:bool <- greater-or-equal row, screen-height
216   ¦ break-if off-screen?
217   ¦ # if we find old-before-cursor still on the new resized screen, update
218   ¦ # editor.cursor-row and editor.cursor-column based on
219   ¦ # old-before-cursor
220   ¦ {
221   ¦ ¦ at-cursor?:bool <- equal old-before-cursor, prev
222   ¦ ¦ break-unless at-cursor?
223   ¦ ¦ *editor <- put *editor, cursor-row:offset, row
224   ¦ ¦ *editor <- put *editor, cursor-column:offset, column
225   ¦ ¦ *editor <- put *editor, before-cursor:offset, old-before-cursor
226   ¦ }
227   ¦ c:char <- get *curr, value:offset
228   ¦ <character-c-received>
229   ¦ {
230   ¦ ¦ # newline? move to left rather than 0
231   ¦ ¦ newline?:bool <- equal c, 10/newline
232   ¦ ¦ break-unless newline?
233   ¦ ¦ # clear rest of line in this window
234   ¦ ¦ clear-line-until screen, right
235   ¦ ¦ # skip to next line
236   ¦ ¦ row <- add row, 1
237   ¦ ¦ column <- copy left
238   ¦ ¦ screen <- move-cursor screen, row, column
239   ¦ ¦ curr <- next curr
240   ¦ ¦ prev <- next prev
241   ¦ ¦ loop +next-character
242   ¦ }
243   ¦ {
244   ¦ ¦ # at right? wrap. even if there's only one more letter left; we need
245   ¦ ¦ # room for clicking on the cursor after it.
246   ¦ ¦ at-right?:bool <- equal column, right
247   ¦ ¦ break-unless at-right?
248   ¦ ¦ # print wrap icon
249   ¦ ¦ wrap-icon:char <- copy 8617/loop-back-to-left
250   ¦ ¦ print screen, wrap-icon, 245/grey
251   ¦ ¦ column <- copy left
252   ¦ ¦ row <- add row, 1
253   ¦ ¦ screen <- move-cursor screen, row, column
254   ¦ ¦ # don't increment curr
255   ¦ ¦ loop +next-character
256   ¦ }
257   ¦ print screen, c, color
258   ¦ curr <- next curr
259   ¦ prev <- next prev
260   ¦ column <- add column, 1
261   ¦ loop
262   }
263   # save first character off-screen
264   *editor <- put *editor, bottom-of-screen:offset, curr
265   *editor <- put *editor, bottom:offset, row
266   return row, column
267 ]
268 
269 scenario point-at-multiple-editors [
270   local-scope
271   trace-until 100/app  # trace too long
272   assume-screen 30/width, 5/height
273   # initialize both halves of screen
274   assume-resources [
275   ¦ [lesson/recipes.mu] <- [
276   ¦ ¦ |abc|
277   ¦ ]
278   ]
279   env:&:environment <- new-programming-environment resources, screen, [def]  # contents of sandbox editor
280   # focus on both sides
281   assume-console [
282   ¦ left-click 1, 1
283   ¦ left-click 1, 17
284   ]
285   # check cursor column in each
286   run [
287   ¦ event-loop screen, console, env, resources
288   ¦ recipes:&:editor <- get *env, recipes:offset
289   ¦ 5:num/raw <- get *recipes, cursor-column:offset
290   ¦ sandbox:&:editor <- get *env, current-sandbox:offset
291   ¦ 7:num/raw <- get *sandbox, cursor-column:offset
292   ]
293   memory-should-contain [
294   ¦ 5 <- 1
295   ¦ 7 <- 17
296   ]
297 ]
298 
299 scenario edit-multiple-editors [
300   local-scope
301   trace-until 100/app  # trace too long
302   assume-screen 30/width, 5/height
303   # initialize both halves of screen
304   assume-resources [
305   ¦ [lesson/recipes.mu] <- [
306   ¦ ¦ |abc|
307   ¦ ]
308   ]
309   env:&:environment <- new-programming-environment resources, screen, [def]  # contents of sandbox
310   render-all screen, env, render
311   # type one letter in each of them
312   assume-console [
313   ¦ left-click 1, 1
314   ¦ type [0]
315   ¦ left-click 1, 17
316   ¦ type [1]
317   ]
318   run [
319   ¦ event-loop screen, console, env, resources
320   ¦ recipes:&:editor <- get *env, recipes:offset
321   ¦ 5:num/raw <- get *recipes, cursor-column:offset
322   ¦ sandbox:&:editor <- get *env, current-sandbox:offset
323   ¦ 7:num/raw <- get *sandbox, cursor-column:offset
324   ]
325   screen-should-contain [
326   ¦ .           run (F4)           .  # this line has a different background, but we don't test that yet
327   ¦ .a0bc           ╎d1ef          .
328   ¦ .               ╎──────────────.
329   ¦ .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .
330   ¦ .               ╎              .
331   ]
332   memory-should-contain [
333   ¦ 5 <- 2  # cursor column of recipe editor
334   ¦ 7 <- 18  # cursor column of sandbox editor
335   ]
336   # show the cursor at the right window
337   run [
338   ¦ cursor:char <- copy 9251/␣
339   ¦ print screen, cursor
340   ]
341   screen-should-contain [
342   ¦ .           run (F4)           .
343   ¦ .a0bc           ╎d1␣f          .
344   ¦ .               ╎──────────────.
345   ¦ .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .
346   ¦ .               ╎              .
347   ]
348 ]
349 
350 scenario editor-in-focus-keeps-cursor [
351   local-scope
352   trace-until 100/app  # trace too long
353   assume-screen 30/width, 5/height
354   assume-resources [
355   ¦ [lesson/recipes.mu] <- [
356   ¦ ¦ |abc|
357   ¦ ]
358   ]
359   env:&:environment <- new-programming-environment resources, screen, [def]
360   render-all screen, env, render
361   # initialize programming environment and highlight cursor
362   assume-console []
363   run [
364   ¦ event-loop screen, console, env, resources
365   ¦ cursor:char <- copy 9251/␣
366   ¦ print screen, cursor
367   ]
368   # is cursor at the right place?
369   screen-should-contain [
370   ¦ .           run (F4)           .
371   ¦ .␣bc            ╎def           .
372   ¦ .               ╎──────────────.
373   ¦ .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .
374   ¦ .               ╎              .
375   ]
376   # now try typing a letter
377   assume-console [
378   ¦ type [z]
379   ]
380   run [
381   ¦ event-loop screen, console, env, resources
382   ¦ cursor:char <- copy 9251/␣
383   ¦ print screen, cursor
384   ]
385   # cursor should still be right
386   screen-should-contain [
387   ¦ .           run (F4)           .
388   ¦ .z␣bc           ╎def           .
389   ¦ .               ╎──────────────.
390   ¦ .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .
391   ¦ .               ╎              .
392   ]
393 ]
394 
395 scenario backspace-in-sandbox-editor-joins-lines [
396   local-scope
397   trace-until 100/app  # trace too long
398   assume-screen 30/width, 5/height
399   assume-resources [
400   ]
401   # initialize sandbox side with two lines
402   test-sandbox-editor-contents:text <- new [abc
403 def]
404   env:&:environment <- new-programming-environment resources, screen, test-sandbox-editor-contents
405   render-all screen, env, render
406   screen-should-contain [
407   ¦ .           run (F4)           .
408   ¦ .               ╎abc           .
409   ¦ .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎def           .
410   ¦ .               ╎──────────────.
411   ¦ .               ╎              .
412   ]
413   # position cursor at start of second line and hit backspace
414   assume-console [
415   ¦ left-click 2, 16
416   ¦ press backspace
417   ]
418   run [
419   ¦ event-loop screen, console, env, resources
420   ¦ cursor:char <- copy 9251/␣
421   ¦ print screen, cursor
422   ]
423   # cursor moves to end of old line
424   screen-should-contain [
425   ¦ .           run (F4)           .
426   ¦ .               ╎abc␣ef        .
427   ¦ .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎──────────────.
428   ¦ .               ╎              .
429   ]
430 ]
431 
432 def render-all screen:&:screen, env:&:environment, {render-editor: (recipe (address screen) (address editor) -> number number (address screen) (address editor))} -> screen:&:screen, env:&:environment [
433   local-scope
434   load-ingredients
435   trace 10, [app], [render all]
436   # top menu
437   trace 11, [app], [render top menu]
438   width:num <- screen-width screen
439   draw-horizontal screen, 0, 0/left, width, 32/space, 0/black, 238/grey
440   button-start:num <- subtract width, 20
441   button-on-screen?:bool <- greater-or-equal button-start, 0
442   assert button-on-screen?, [screen too narrow for menu]
443   screen <- move-cursor screen, 0/row, button-start
444   print screen, [ run (F4) ], 255/white, 161/reddish
445   # dotted line down the middle
446   trace 11, [app], [render divider]
447   divider:num, _ <- divide-with-remainder width, 2
448   height:num <- screen-height screen
449   draw-vertical screen, divider, 1/top, height, 9482/vertical-dotted
450   #
451   screen <- render-recipes screen, env, render-editor
452   screen <- render-sandbox-side screen, env, render-editor
453   <render-components-end>
454   #
455   recipes:&:editor <- get *env, recipes:offset
456   current-sandbox:&:editor <- get *env, current-sandbox:offset
457   sandbox-in-focus?:bool <- get *env, sandbox-in-focus?:offset
458   screen <- update-cursor screen, recipes, current-sandbox, sandbox-in-focus?, env
459 ]
460 
461 def render-recipes screen:&:screen, env:&:environment, {render-editor: (recipe (address screen) (address editor) -> number number (address screen) (address editor))} -> screen:&:screen, env:&:environment [
462   local-scope
463   load-ingredients
464   trace 11, [app], [render recipes]
465   recipes:&:editor <- get *env, recipes:offset
466   # render recipes
467   left:num <- get *recipes, left:offset
468   right:num <- get *recipes, right:offset
469   row:num, column:num, screen <- call render-editor, screen, recipes
470   clear-line-until screen, right
471   row <- add row, 1
472   <render-recipe-components-end>
473   # draw dotted line after recipes
474   draw-horizontal screen, row, left, right, 9480/horizontal-dotted
475   row <- add row, 1
476   clear-screen-from screen, row, left, left, right
477 ]
478 
479 # replaced in a later layer
480 def render-sandbox-side screen:&:screen, env:&:environment, {render-editor: (recipe (address screen) (address editor) -> number number (address screen) (address editor))} -> screen:&:screen, env:&:environment [
481   local-scope
482   load-ingredients
483   current-sandbox:&:editor <- get *env, current-sandbox:offset
484   left:num <- get *current-sandbox, left:offset
485   right:num <- get *current-sandbox, right:offset
486   row:num, column:num, screen, current-sandbox <- call render-editor, screen, current-sandbox
487   clear-line-until screen, right
488   row <- add row, 1
489   # draw solid line after code (you'll see why in later layers)
490   draw-horizontal screen, row, left, right
491   row <- add row, 1
492   clear-screen-from screen, row, left, left, right
493 ]
494 
495 def update-cursor screen:&:screen, recipes:&:editor, current-sandbox:&:editor, sandbox-in-focus?:bool, env:&:environment -> screen:&:screen [
496   local-scope
497   load-ingredients
498   <update-cursor-special-cases>
499   {
500   ¦ break-if sandbox-in-focus?
501   ¦ cursor-row:num <- get *recipes, cursor-row:offset
502   ¦ cursor-column:num <- get *recipes, cursor-column:offset
503   }
504   {
505   ¦ break-unless sandbox-in-focus?
506   ¦ cursor-row:num <- get *current-sandbox, cursor-row:offset
507   ¦ cursor-column:num <- get *current-sandbox, cursor-column:offset
508   }
509   screen <- move-cursor screen, cursor-row, cursor-column
510 ]
511 
512 # ctrl-n - switch focus
513 # todo: test this
514 
515 after <global-type> [
516   {
517   ¦ switch-side?:bool <- equal c, 14/ctrl-n
518   ¦ break-unless switch-side?
519   ¦ sandbox-in-focus?:bool <- get *env, sandbox-in-focus?:offset
520   ¦ sandbox-in-focus? <- not sandbox-in-focus?
521   ¦ *env <- put *env, sandbox-in-focus?:offset, sandbox-in-focus?
522   ¦ screen <- update-cursor screen, recipes, current-sandbox, sandbox-in-focus?, env
523   ¦ loop +next-event
524   }
525 ]
526 
527 ## helpers
528 
529 def draw-vertical screen:&:screen, col:num, y:num, bottom:num -> screen:&:screen [
530   local-scope
531   load-ingredients
532   style:char, style-found?:bool <- next-ingredient
533   {
534   ¦ break-if style-found?
535   ¦ style <- copy 9474/vertical
536   }
537   color:num, color-found?:bool <- next-ingredient
538   {
539   ¦ # default color to white
540   ¦ break-if color-found?
541   ¦ color <- copy 245/grey
542   }
543   {
544   ¦ continue?:bool <- lesser-than y, bottom
545   ¦ break-unless continue?
546   ¦ screen <- move-cursor screen, y, col
547   ¦ print screen, style, color
548   ¦ y <- add y, 1
549   ¦ loop
550   }
551 ]