3698

Update sandbox/ with recent changes to edit/ (commit 3695 onwards).

[Incidentally, this is the first commit to be made while running on
OpenBSD. Simulated and host systems are going to blur together from now
on.]

6 files changed, 148 insertions, 142 deletions

diff --git a/sandbox/001-editor.mu b/sandbox/001-editor.mu
index 54a35391..170468cd 100644
--- a/sandbox/001-editor.mu
+++ b/sandbox/001-editor.mu
@@ -7,17 +7,18 @@ def! main text:text [
   load-ingredients
   open-console
   hide-screen 0/screen
-  new-editor text, 0/screen, 0/left, 5/right
+  new-editor text, 0/left, 5/right
   show-screen 0/screen
   wait-for-event 0/console
   close-console
 ]
 
-scenario editor-initially-prints-text-to-screen [
+scenario editor-renders-text-to-screen [
   local-scope
   assume-screen 10/width, 5/height
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   run [
-    new-editor [abc], screen, 0/left, 10/right
+    render screen, e
   ]
   screen-should-contain [
     # top line of screen reserved for menu
@@ -45,10 +46,9 @@ container editor [
   cursor-column:num
 ]
 
-# creates a new editor widget and renders its initial appearance to screen
-#   top/left/right constrain the screen area available to the new editor
+# creates a new editor widget
 #   right is exclusive
-def new-editor s:text, screen:&:screen, left:num, right:num -> result:&:editor, screen:&:screen [
+def new-editor s:text, left:num, right:num -> result:&:editor [
   local-scope
   load-ingredients
   # no clipping of bounds
@@ -66,8 +66,6 @@ def new-editor s:text, screen:&:screen, left:num, right:num -> result:&:editor,
   *result <- put *result, top-of-screen:offset, init
   *result <- put *result, before-cursor:offset, init
   result <- insert-text result, s
-  # initial render to screen, just for some old tests
-  _, _, screen, result <- render screen, result
   <editor-initialization>
 ]
 
@@ -98,7 +96,7 @@ scenario editor-initializes-without-data [
   local-scope
   assume-screen 5/width, 3/height
   run [
-    e:&:editor <- new-editor 0/data, screen, 2/left, 5/right
+    e:&:editor <- new-editor 0/data, 2/left, 5/right
     2:editor/raw <- copy *e
   ]
   memory-should-contain [
@@ -108,7 +106,7 @@ scenario editor-initializes-without-data [
     # 5 (before cursor) <- the § sentinel
     6 <- 2  # left
     7 <- 4  # right  (inclusive)
-    8 <- 1  # bottom
+    8 <- 0  # bottom (not set until render)
     9 <- 1  # cursor row
     10 <- 2  # cursor column
   ]
@@ -255,13 +253,14 @@ def clear-rest-of-screen screen:&:screen, row:num, left:num, right:num -> screen
   }
 ]
 
-scenario editor-initially-prints-multiple-lines [
+scenario editor-prints-multiple-lines [
   local-scope
   assume-screen 5/width, 5/height
-  run [
-    s:text <- new [abc
+  s:text <- new [abc
 def]
-    new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
+  run [
+    render screen, e
   ]
   screen-should-contain [
     .     .
@@ -271,12 +270,12 @@ def]
   ]
 ]
 
-scenario editor-initially-handles-offsets [
+scenario editor-handles-offsets [
   local-scope
   assume-screen 5/width, 5/height
+  e:&:editor <- new-editor [abc], 1/left, 5/right
   run [
-    s:text <- new [abc]
-    new-editor s, screen, 1/left, 5/right
+    render screen, e
   ]
   screen-should-contain [
     .     .
@@ -285,13 +284,14 @@ scenario editor-initially-handles-offsets [
   ]
 ]
 
-scenario editor-initially-prints-multiple-lines-at-offset [
+scenario editor-prints-multiple-lines-at-offset [
   local-scope
   assume-screen 5/width, 5/height
-  run [
-    s:text <- new [abc
+  s:text <- new [abc
 def]
-    new-editor s, screen, 1/left, 5/right
+  e:&:editor <- new-editor s, 1/left, 5/right
+  run [
+    render screen, e
   ]
   screen-should-contain [
     .     .
@@ -301,12 +301,12 @@ def]
   ]
 ]
 
-scenario editor-initially-wraps-long-lines [
+scenario editor-wraps-long-lines [
   local-scope
   assume-screen 5/width, 5/height
+  e:&:editor <- new-editor [abc def], 0/left, 5/right
   run [
-    s:text <- new [abc def]
-    new-editor s, screen, 0/left, 5/right
+    render screen, e
   ]
   screen-should-contain [
     .     .
@@ -322,12 +322,12 @@ scenario editor-initially-wraps-long-lines [
   ]
 ]
 
-scenario editor-initially-wraps-barely-long-lines [
+scenario editor-wraps-barely-long-lines [
   local-scope
   assume-screen 5/width, 5/height
+  e:&:editor <- new-editor [abcde], 0/left, 5/right
   run [
-    s:text <- new [abcde]
-    new-editor s, screen, 0/left, 5/right
+    render screen, e
   ]
   # still wrap, even though the line would fit. We need room to click on the
   # end of the line
@@ -345,11 +345,12 @@ scenario editor-initially-wraps-barely-long-lines [
   ]
 ]
 
-scenario editor-initializes-empty-text [
+scenario editor-with-empty-text [
   local-scope
   assume-screen 5/width, 5/height
+  e:&:editor <- new-editor [], 0/left, 5/right
   run [
-    e:&:editor <- new-editor [], screen, 0/left, 5/right
+    render screen, e
     3:num/raw <- get *e, cursor-row:offset
     4:num/raw <- get *e, cursor-column:offset
   ]
@@ -369,11 +370,12 @@ scenario editor-initializes-empty-text [
 scenario render-colors-comments [
   local-scope
   assume-screen 5/width, 5/height
-  run [
-    s:text <- new [abc
+  s:text <- new [abc
 # de
 f]
-    new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
+  run [
+    render screen, e
   ]
   screen-should-contain [
     .     .
@@ -451,11 +453,12 @@ def get-color color:num, c:char -> color:num [
 scenario render-colors-assignment [
   local-scope
   assume-screen 8/width, 5/height
-  run [
-    s:text <- new [abc
+  s:text <- new [abc
 d <- e
 f]
-    new-editor s, screen, 0/left, 8/right
+  e:&:editor <- new-editor s, 0/left, 8/right
+  run [
+    render screen, e
   ]
   screen-should-contain [
     .        .
diff --git a/sandbox/002-typing.mu b/sandbox/002-typing.mu
index 906422f5..a584e6a3 100644
--- a/sandbox/002-typing.mu
+++ b/sandbox/002-typing.mu
@@ -6,7 +6,7 @@ def! main text:text [
   local-scope
   load-ingredients
   open-console
-  editor:&:editor <- new-editor text, 0/screen, 5/left, 45/right
+  editor:&:editor <- new-editor text, 5/left, 45/right
   editor-event-loop 0/screen, 0/console, editor
   close-console
 ]
@@ -283,7 +283,7 @@ def editor-render screen:&:screen, editor:&:editor -> screen:&:screen, editor:&:
 scenario editor-handles-empty-event-queue [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   assume-console []
   run [
@@ -300,7 +300,7 @@ scenario editor-handles-empty-event-queue [
 scenario editor-handles-mouse-clicks [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -327,7 +327,7 @@ scenario editor-handles-mouse-clicks [
 scenario editor-handles-mouse-clicks-outside-text [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   $clear-trace
   assume-console [
     left-click 1, 7  # last line, to the right of text
@@ -349,7 +349,7 @@ scenario editor-handles-mouse-clicks-outside-text-2 [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 def]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   $clear-trace
   assume-console [
     left-click 1, 7  # interior line, to the right of text
@@ -371,7 +371,7 @@ scenario editor-handles-mouse-clicks-outside-text-3 [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 def]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   $clear-trace
   assume-console [
     left-click 3, 7  # below text
@@ -392,7 +392,7 @@ scenario editor-handles-mouse-clicks-outside-column [
   local-scope
   assume-screen 10/width, 5/height
   # editor occupies only left half of screen
-  e:&:editor <- new-editor [abc], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abc], 0/left, 5/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -420,7 +420,7 @@ scenario editor-handles-mouse-clicks-outside-column [
 scenario editor-handles-mouse-clicks-in-menu-area [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abc], 0/left, 5/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -442,7 +442,7 @@ scenario editor-handles-mouse-clicks-in-menu-area [
 scenario editor-inserts-characters-into-empty-editor [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 5/right
+  e:&:editor <- new-editor [], 0/left, 5/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -463,7 +463,7 @@ scenario editor-inserts-characters-into-empty-editor [
 scenario editor-inserts-characters-at-cursor [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # type two letters at different places
@@ -487,7 +487,7 @@ scenario editor-inserts-characters-at-cursor [
 scenario editor-inserts-characters-at-cursor-2 [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -511,7 +511,7 @@ scenario editor-inserts-characters-at-cursor-5 [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -534,7 +534,7 @@ d]
 scenario editor-inserts-characters-at-cursor-3 [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -558,7 +558,7 @@ scenario editor-inserts-characters-at-cursor-4 [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -583,7 +583,7 @@ scenario editor-inserts-characters-at-cursor-6 [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -606,7 +606,7 @@ d]
 scenario editor-moves-cursor-after-inserting-characters [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [ab], screen, 0/left, 5/right
+  e:&:editor <- new-editor [ab], 0/left, 5/right
   editor-render screen, e
   assume-console [
     type [01]
@@ -627,7 +627,7 @@ scenario editor-moves-cursor-after-inserting-characters [
 scenario editor-wraps-line-on-insert [
   local-scope
   assume-screen 5/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abc], 0/left, 5/right
   editor-render screen, e
   # type a letter
   assume-console [
@@ -667,7 +667,7 @@ scenario editor-wraps-line-on-insert-2 [
   assume-screen 10/width, 5/height
   s:text <- new [abcdefg
 defg]
-  e:&:editor <- new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
   editor-render screen, e
   # type more text at the start
   assume-console [
@@ -748,7 +748,7 @@ after <insert-character-special-case> [
 scenario editor-wraps-cursor-after-inserting-characters-in-middle-of-line [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abcde], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abcde], 0/left, 5/right
   assume-console [
     left-click 1, 3  # right before the wrap icon
     type [f]
@@ -777,11 +777,13 @@ scenario editor-wraps-cursor-after-inserting-characters-at-end-of-line [
   # create an editor containing two lines
   s:text <- new [abc
 xyz]
-  e:&:editor <- new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
+  editor-render screen, e
   screen-should-contain [
     .          .
     .abc       .
     .xyz       .
+    .┈┈┈┈┈     .
     .          .
   ]
   assume-console [
@@ -803,7 +805,7 @@ xyz]
 scenario editor-wraps-cursor-to-left-margin [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abcde], screen, 2/left, 7/right
+  e:&:editor <- new-editor [abcde], 2/left, 7/right
   assume-console [
     left-click 1, 5  # line is full; no wrap icon yet
     type [01]
@@ -839,7 +841,7 @@ after <editor-initialization> [
 scenario editor-moves-cursor-down-after-inserting-newline [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   assume-console [
     type [0
 1]
@@ -945,7 +947,7 @@ def line-indent curr:&:duplex-list:char, start:&:duplex-list:char -> result:num
 scenario editor-moves-cursor-down-after-inserting-newline-2 [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 1/left, 10/right
+  e:&:editor <- new-editor [abc], 1/left, 10/right
   assume-console [
     type [0
 1]
@@ -965,16 +967,17 @@ scenario editor-moves-cursor-down-after-inserting-newline-2 [
 scenario editor-clears-previous-line-completely-after-inserting-newline [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abcde], screen, 0/left, 5/right
-  assume-console [
-    press enter
-  ]
+  e:&:editor <- new-editor [abcde], 0/left, 5/right
+  editor-render screen, e
   screen-should-contain [
     .          .
     .abcd↩     .
     .e         .
+    .┈┈┈┈┈     .
     .          .
-    .          .
+  ]
+  assume-console [
+    press enter
   ]
   run [
     editor-event-loop screen, console, e
@@ -995,7 +998,7 @@ scenario editor-inserts-indent-after-newline [
   s:text <- new [ab
   cd
 ef]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # position cursor after 'cd' and hit 'newline'
   assume-console [
     left-click 2, 8
@@ -1020,7 +1023,7 @@ scenario editor-skips-indent-around-paste [
   s:text <- new [ab
   cd
 ef]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # position cursor after 'cd' and hit 'newline' surrounded by paste markers
   assume-console [
     left-click 2, 8
diff --git a/sandbox/003-shortcuts.mu b/sandbox/003-shortcuts.mu
index 7c5d0df2..248c2c64 100644
--- a/sandbox/003-shortcuts.mu
+++ b/sandbox/003-shortcuts.mu
@@ -10,7 +10,7 @@ scenario editor-inserts-two-spaces-on-tab [
   # just one character in final line
   s:text <- new [ab
 cd]
-  e:&:editor <- new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
   assume-console [
     press tab
   ]
@@ -42,7 +42,7 @@ after <handle-special-character> [
 scenario editor-handles-backspace-key [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -216,7 +216,7 @@ scenario editor-clears-last-line-on-backspace [
   # just one character in final line
   s:text <- new [ab
 cd]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   assume-console [
     left-click 2, 0  # cursor at only character in final line
     press backspace
@@ -244,7 +244,7 @@ scenario editor-joins-and-wraps-lines-on-backspace [
   # initialize editor with two long-ish but non-wrapping lines
   s:text <- new [abc def
 ghi jkl]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # position the cursor at the start of the second and hit backspace
@@ -269,7 +269,7 @@ scenario editor-wraps-long-lines-on-backspace [
   local-scope
   assume-screen 10/width, 5/height
   # initialize editor in part of the screen with a long line
-  e:&:editor <- new-editor [abc def ghij], screen, 0/left, 8/right
+  e:&:editor <- new-editor [abc def ghij], 0/left, 8/right
   editor-render screen, e
   # confirm that it wraps
   screen-should-contain [
@@ -302,7 +302,7 @@ scenario editor-wraps-long-lines-on-backspace [
 scenario editor-handles-delete-key [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -391,7 +391,7 @@ def delete-at-cursor editor:&:editor, screen:&:screen -> editor:&:editor, screen
 scenario editor-moves-cursor-right-with-key [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -488,7 +488,7 @@ scenario editor-moves-cursor-to-next-line-with-right-arrow [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # type right-arrow a few times to get to start of second line
@@ -524,7 +524,7 @@ scenario editor-moves-cursor-to-next-line-with-right-arrow-2 [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 1/left, 10/right
+  e:&:editor <- new-editor s, 1/left, 10/right
   editor-render screen, e
   assume-console [
     press right-arrow
@@ -548,7 +548,7 @@ d]
 scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abcdef], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abcdef], 0/left, 5/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -578,7 +578,7 @@ scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow-2 [
   local-scope
   assume-screen 10/width, 5/height
   # line just barely wrapping
-  e:&:editor <- new-editor [abcde], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abcde], 0/left, 5/right
   editor-render screen, e
   $clear-trace
   # position cursor at last character before wrap and hit right-arrow
@@ -614,7 +614,7 @@ scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow-2 [
 scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow-3 [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abcdef], screen, 1/left, 6/right
+  e:&:editor <- new-editor [abcdef], 1/left, 6/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -645,7 +645,7 @@ scenario editor-moves-cursor-to-next-line-with-right-arrow-at-end-of-line [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # move to end of line, press right-arrow, type a character
@@ -675,7 +675,7 @@ d]
 scenario editor-moves-cursor-left-with-key [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -720,7 +720,7 @@ scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line [
   # initialize editor with two lines
   s:text <- new [abc
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # position cursor at start of second line (so there's no previous newline)
@@ -747,7 +747,7 @@ scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-2
   s:text <- new [abc
 def
 g]
-  e:&:editor <- new-editor s:text, screen, 0/left, 10/right
+  e:&:editor <- new-editor s:text, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # position cursor further down (so there's a newline before the character at
@@ -776,7 +776,7 @@ scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-3
   s:text <- new [abc
 def
 g]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # position cursor at start of text, press left-arrow, then type a character
@@ -806,7 +806,7 @@ scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-4
   s:text <- new [abc
 
 d]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e:&:editor
   $clear-trace
   # position cursor right after empty line
@@ -832,7 +832,7 @@ scenario editor-moves-across-screen-lines-across-wrap-with-left-arrow [
   local-scope
   assume-screen 10/width, 5/height
   # initialize editor with a wrapping line
-  e:&:editor <- new-editor [abcdef], screen, 0/left, 5/right
+  e:&:editor <- new-editor [abcdef], 0/left, 5/right
   editor-render screen, e
   $clear-trace
   screen-should-contain [
@@ -865,7 +865,7 @@ scenario editor-moves-across-screen-lines-to-wrapping-line-with-left-arrow [
   # initialize editor with a wrapping line followed by a second line
   s:text <- new [abcdef
 g]
-  e:&:editor <- new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
   editor-render screen, e
   $clear-trace
   screen-should-contain [
@@ -898,7 +898,7 @@ scenario editor-moves-across-screen-lines-to-non-wrapping-line-with-left-arrow [
   # initialize editor with a line on the verge of wrapping, followed by a second line
   s:text <- new [abcd
 e]
-  e:&:editor <- new-editor s, screen, 0/left, 5/right
+  e:&:editor <- new-editor s, 0/left, 5/right
   editor-render screen, e
   $clear-trace
   screen-should-contain [
@@ -934,7 +934,7 @@ scenario editor-moves-to-previous-line-with-up-arrow [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 def]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -1050,7 +1050,7 @@ scenario editor-adjusts-column-at-previous-line [
   assume-screen 10/width, 5/height
   s:text <- new [ab
 def]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -1087,7 +1087,7 @@ scenario editor-adjusts-column-at-empty-line [
   assume-screen 10/width, 5/height
   s:text <- new [
 def]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -1126,7 +1126,7 @@ scenario editor-moves-to-previous-line-from-left-margin [
   s:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # click on the third line and hit up-arrow, so you end up just after a newline
@@ -1166,7 +1166,7 @@ scenario editor-moves-to-next-line-with-down-arrow [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 def]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # cursor starts out at (1, 0)
@@ -1258,7 +1258,7 @@ scenario editor-adjusts-column-at-next-line [
   assume-screen 10/width, 5/height
   s:text <- new [abc
 de]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   assume-console [
@@ -1297,7 +1297,7 @@ scenario editor-moves-to-start-of-line-with-ctrl-a [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on second line, press ctrl-a
@@ -1373,7 +1373,7 @@ scenario editor-moves-to-start-of-line-with-ctrl-a-2 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on first line (no newline before), press ctrl-a
@@ -1399,7 +1399,7 @@ scenario editor-moves-to-start-of-line-with-home [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   $clear-trace
   # start on second line, press 'home'
   assume-console [
@@ -1424,7 +1424,7 @@ scenario editor-moves-to-start-of-line-with-home-2 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on first line (no newline before), press 'home'
@@ -1452,7 +1452,7 @@ scenario editor-moves-to-end-of-line-with-ctrl-e [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on first line, press ctrl-e
@@ -1545,7 +1545,7 @@ scenario editor-moves-to-end-of-line-with-ctrl-e-2 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on second line (no newline after), press ctrl-e
@@ -1571,7 +1571,7 @@ scenario editor-moves-to-end-of-line-with-end [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on first line, press 'end'
@@ -1597,7 +1597,7 @@ scenario editor-moves-to-end-of-line-with-end-2 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   editor-render screen, e
   $clear-trace
   # start on second line (no newline after), press 'end'
@@ -1625,7 +1625,7 @@ scenario editor-deletes-to-start-of-line-with-ctrl-u [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start on second line, press ctrl-u
   assume-console [
     left-click 2, 2
@@ -1689,7 +1689,7 @@ scenario editor-deletes-to-start-of-line-with-ctrl-u-2 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start on first line (no newline before), press ctrl-u
   assume-console [
     left-click 1, 2
@@ -1713,7 +1713,7 @@ scenario editor-deletes-to-start-of-line-with-ctrl-u-3 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start past end of line, press ctrl-u
   assume-console [
     left-click 1, 3
@@ -1737,7 +1737,7 @@ scenario editor-deletes-to-start-of-final-line-with-ctrl-u [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start past end of final line, press ctrl-u
   assume-console [
     left-click 2, 3
@@ -1763,7 +1763,7 @@ scenario editor-deletes-to-end-of-line-with-ctrl-k [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start on first line, press ctrl-k
   assume-console [
     left-click 1, 1
@@ -1819,7 +1819,7 @@ scenario editor-deletes-to-end-of-line-with-ctrl-k-2 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start on second line (no newline after), press ctrl-k
   assume-console [
     left-click 2, 1
@@ -1843,7 +1843,7 @@ scenario editor-deletes-to-end-of-line-with-ctrl-k-3 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start at end of line
   assume-console [
     left-click 1, 2
@@ -1867,7 +1867,7 @@ scenario editor-deletes-to-end-of-line-with-ctrl-k-4 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start past end of line
   assume-console [
     left-click 1, 3
@@ -1891,7 +1891,7 @@ scenario editor-deletes-to-end-of-line-with-ctrl-k-5 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start at end of text
   assume-console [
     left-click 2, 2
@@ -1915,7 +1915,7 @@ scenario editor-deletes-to-end-of-line-with-ctrl-k-6 [
   assume-screen 10/width, 5/height
   s:text <- new [123
 456]
-  e:&:editor <- new-editor s, screen, 0/left, 10/right
+  e:&:editor <- new-editor s, 0/left, 10/right
   # start past end of text
   assume-console [
     left-click 2, 3
diff --git a/sandbox/004-programming-environment.mu b/sandbox/004-programming-environment.mu
index 57eff09f..be55c7ee 100644
--- a/sandbox/004-programming-environment.mu
+++ b/sandbox/004-programming-environment.mu
@@ -33,7 +33,7 @@ def new-programming-environment screen:&:screen, initial-sandbox-contents:text -
   screen <- move-cursor screen, 0/row, button-start
   print screen, [ run (F4) ], 255/white, 161/reddish
   # sandbox editor
-  current-sandbox:&:editor <- new-editor initial-sandbox-contents, screen, 0, width/right
+  current-sandbox:&:editor <- new-editor initial-sandbox-contents, 0, width/right
   *result <- put *result, current-sandbox:offset, current-sandbox
   <programming-environment-initialization>
 ]
diff --git a/sandbox/005-sandbox.mu b/sandbox/005-sandbox.mu
index 7787b50c..9fd2a08b 100644
--- a/sandbox/005-sandbox.mu
+++ b/sandbox/005-sandbox.mu
@@ -1,14 +1,14 @@
 ## running code from the editor and creating sandboxes
 #
 # Running code in the sandbox editor prepends its contents to a list of
-# (non-editable) sandboxes below the editor, showing the result and a maybe
-# few other things.
+# (non-editable) sandboxes below the editor, showing the result and maybe a
+# few other things (later layers).
 #
-# This layer draws the menubar buttons non-editable sandboxes but they don't
-# do anything yet. Later layers implement each button.
+# This layer draws the menubar buttons in non-editable sandboxes but they
+# don't do anything yet. Later layers implement each button.
 
 container environment [
-  sandbox:&:sandbox  # list of sandboxes, from top to bottom
+  sandbox:&:sandbox  # list of sandboxes, from top to bottom. TODO: switch to &:list:sandbox
   render-from:num
   number-of-sandboxes:num
 ]
@@ -110,7 +110,7 @@ after <global-keypress> [
     screen <- update-status screen, [running...       ], 245/grey
     test-recipes:text, _/optional <- next-ingredient
     error?:bool, env, screen <- run-sandboxes env, screen, test-recipes
-#?     test-recipes <- copy 0  # abandon
+    test-recipes <- copy 0  # abandon
     # F4 might update warnings and results on both sides
     screen <- render-all screen, env, render
     {
@@ -607,7 +607,7 @@ def editor-contents editor:&:editor -> result:text [
 scenario editor-provides-edited-contents [
   local-scope
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [abc], 0/left, 10/right
   assume-console [
     left-click 1, 2
     type [def]
diff --git a/sandbox/012-editor-undo.mu b/sandbox/012-editor-undo.mu
index 27f49377..bc37f307 100644
--- a/sandbox/012-editor-undo.mu
+++ b/sandbox/012-editor-undo.mu
@@ -102,7 +102,7 @@ scenario editor-can-undo-typing [
   local-scope
   # create an editor and type a character
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   assume-console [
     type [0]
@@ -232,7 +232,7 @@ scenario editor-can-undo-typing-multiple [
   local-scope
   # create an editor and type multiple characters
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   assume-console [
     type [012]
@@ -258,7 +258,7 @@ scenario editor-can-undo-typing-multiple-2 [
   local-scope
   # create an editor with some text
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [a], screen, 0/left, 10/right
+  e:&:editor <- new-editor [a], 0/left, 10/right
   editor-render screen, e
   # type some characters
   assume-console [
@@ -304,7 +304,7 @@ scenario editor-can-undo-typing-enter [
   local-scope
   # create an editor with some text
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [  abc], screen, 0/left, 10/right
+  e:&:editor <- new-editor [  abc], 0/left, 10/right
   editor-render screen, e
   # new line
   assume-console [
@@ -367,7 +367,7 @@ scenario editor-redo-typing [
   local-scope
   # create an editor, type something, undo
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [a], screen, 0/left, 10/right
+  e:&:editor <- new-editor [a], 0/left, 10/right
   editor-render screen, e
   assume-console [
     type [012]
@@ -431,7 +431,7 @@ scenario editor-redo-typing-empty [
   local-scope
   # create an editor, type something, undo
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   assume-console [
     type [012]
@@ -480,7 +480,7 @@ scenario editor-work-clears-redo-stack [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   assume-console [
     type [1]
@@ -520,7 +520,7 @@ scenario editor-can-redo-typing-and-enter-and-tab [
   local-scope
   # create an editor
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   # insert some text and tabs, hit enter, some more text and tabs
   assume-console [
@@ -680,7 +680,7 @@ scenario editor-can-undo-touch [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor
   assume-console [
@@ -771,7 +771,7 @@ scenario editor-can-undo-left-arrow [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor
   assume-console [
@@ -816,7 +816,7 @@ scenario editor-can-undo-up-arrow [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor
   assume-console [
@@ -867,7 +867,7 @@ scenario editor-can-undo-down-arrow [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor
   assume-console [
@@ -912,7 +912,7 @@ scenario editor-can-undo-ctrl-a [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor, then to start of line
   assume-console [
@@ -957,7 +957,7 @@ scenario editor-can-undo-home [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor, then to start of line
   assume-console [
@@ -1002,7 +1002,7 @@ scenario editor-can-undo-ctrl-e [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor, then to start of line
   assume-console [
@@ -1047,7 +1047,7 @@ scenario editor-can-undo-end [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor, then to start of line
   assume-console [
@@ -1092,7 +1092,7 @@ scenario editor-can-undo-multiple-arrows-in-the-same-direction [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # move the cursor
   assume-console [
@@ -1147,7 +1147,7 @@ scenario editor-redo-touch [
   contents:text <- new [abc
 def
 ghi]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   assume-console [
     left-click 3, 1
@@ -1202,7 +1202,7 @@ scenario editor-separates-undo-insert-from-undo-cursor-move [
   local-scope
   # create an editor, type some text, move the cursor, type some more text
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   assume-console [
     type [abc]
@@ -1351,7 +1351,7 @@ scenario editor-can-undo-and-redo-backspace [
   local-scope
   # create an editor
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   # insert some text and hit backspace
   assume-console [
@@ -1496,7 +1496,7 @@ scenario editor-can-undo-and-redo-delete [
   local-scope
   # create an editor
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   # insert some text and hit delete and backspace a few times
   assume-console [
@@ -1687,7 +1687,7 @@ scenario editor-can-undo-and-redo-ctrl-k [
   assume-screen 10/width, 5/height
   contents:text <- new [abc
 def]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # insert some text and hit delete and backspace a few times
   assume-console [
@@ -1790,7 +1790,7 @@ scenario editor-can-undo-and-redo-ctrl-u [
   assume-screen 10/width, 5/height
   contents:text <- new [abc
 def]
-  e:&:editor <- new-editor contents, screen, 0/left, 10/right
+  e:&:editor <- new-editor contents, 0/left, 10/right
   editor-render screen, e
   # insert some text and hit delete and backspace a few times
   assume-console [
@@ -1890,7 +1890,7 @@ scenario editor-can-undo-and-redo-ctrl-u-2 [
   local-scope
   # create an editor
   assume-screen 10/width, 5/height
-  e:&:editor <- new-editor [], screen, 0/left, 10/right
+  e:&:editor <- new-editor [], 0/left, 10/right
   editor-render screen, e
   # insert some text and hit delete and backspace a few times
   assume-console [