1718 - delete repl.mu

Focus on the one programming environment from now on: edit.mu. First get
it to print results of computations like repl does, then pipe warnings
into the environment somehow.

1 files changed, 0 insertions, 840 deletions

diff --git a/repl.mu b/repl.mu
deleted file mode 100644
index 80d89e2f..00000000
--- a/repl.mu
+++ /dev/null
@@ -1,840 +0,0 @@
-# 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
-    result:address:array:character <- run-interactive inst:address:array:character
-    print-string screen:address, result:address:array:character
-    print-character screen:address, 10:literal/newline
-    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                             .
-    .                              .
-  ]
-]