## special shortcuts for manipulating the editor
# Some keys on the keyboard generate unicode characters, others generate
# terminfo key codes. We need to modify different places in the two cases.
# tab - insert two spaces
scenario editor-inserts-two-spaces-on-tab [
local-scope
assume-screen 10/width, 5/height
s:text <- new [ab
cd]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
$clear-trace
assume-console [
press tab
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. ab .
.cd .
]
# we render at most two editor rows worth (one row for each space)
check-trace-count-for-label-lesser-than 10, [print-character]
]
scenario editor-inserts-two-spaces-and-wraps-line-on-tab [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abcd], 0/left, 5/right
editor-render screen, e
$clear-trace
assume-console [
press tab
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. ab↩ .
.cd .
]
# we re-render the whole editor
check-trace-count-for-label-greater-than 10, [print-character]
]
after <handle-special-character> [
{
tab?:bool <- equal c, 9/tab
break-unless tab?
<begin-insert-character>
# todo: decompose insert-at-cursor into editor update and screen update,
# so that 'tab' doesn't render the current line multiple times
insert-at-cursor editor, 32/space, screen
go-render? <- insert-at-cursor editor, 32/space, screen
<end-insert-character>
return
}
]
# backspace - delete character before cursor
scenario editor-handles-backspace-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 1
press backspace
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
memory-should-contain [
4 <- 1
5 <- 0
]
check-trace-count-for-label 3, [print-character] # length of original line to overwrite
]
after <handle-special-character> [
{
delete-previous-character?:bool <- equal c, 8/backspace
break-unless delete-previous-character?
<begin-backspace-character>
go-render?:bool, backspaced-cell:&:duplex-list:char <- delete-before-cursor editor, screen
<end-backspace-character>
return
}
]
# return values:
# go-render? - whether caller needs to update the screen
# backspaced-cell - value deleted (or 0 if nothing was deleted) so we can save it for undo, etc.
def delete-before-cursor editor:&:editor, screen:&:screen -> go-render?:bool, backspaced-cell:&:duplex-list:char, editor:&:editor, screen:&:screen [
local-scope
load-inputs
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
data:&:duplex-list:char <- get *editor, data:offset
# if at start of text (before-cursor at § sentinel), return
prev:&:duplex-list:char <- prev before-cursor
return-unless prev, false/no-more-render, null/nothing-deleted
trace 10, [app], [delete-before-cursor]
original-row:num <- get *editor, cursor-row:offset
move-cursor-coordinates-left editor
backspaced-cell:&:duplex-list:char <- copy before-cursor
data <- remove before-cursor, data # will also neatly trim next/prev pointers in backspaced-cell/before-cursor
before-cursor <- copy prev
*editor <- put *editor, before-cursor:offset, before-cursor
screen-width:num <- screen-width screen
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
# did we just backspace over a newline?
same-row?:bool <- equal cursor-row, original-row
return-unless same-row?, true/go-render
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
curr:&:duplex-list:char <- next before-cursor
screen <- move-cursor screen, cursor-row, cursor-column
curr-column:num <- copy cursor-column
{
# hit right margin? give up and let caller render
at-right?:bool <- greater-or-equal curr-column, right
return-if at-right?, true/go-render
break-unless curr
# newline? done.
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
screen <- print screen, currc
curr-column <- add curr-column, 1
curr <- next curr
loop
}
# we're guaranteed not to be at the right margin
space:char <- copy 32/space
screen <- print screen, space
go-render? <- copy false
]
def move-cursor-coordinates-left editor:&:editor -> editor:&:editor [
local-scope
load-inputs
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
left:num <- get *editor, left:offset
# if not at left margin, move one character left
{
at-left-margin?:bool <- equal cursor-column, left
break-if at-left-margin?
trace 10, [app], [decrementing cursor column]
cursor-column <- subtract cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
return
}
# if at left margin, we must move to previous row:
top-of-screen?:bool <- equal cursor-row, 1 # exclude menu bar
{
break-if top-of-screen?
cursor-row <- subtract cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
}
{
break-unless top-of-screen?
# no scroll, so do nothing
}
{
# case 1: if previous character was newline, figure out how long the previous line is
previous-character:char <- get *before-cursor, value:offset
previous-character-is-newline?:bool <- equal previous-character, 10/newline
break-unless previous-character-is-newline?
# compute length of previous line
trace 10, [app], [switching to previous line]
d:&:duplex-list:char <- get *editor, data:offset
end-of-line:num <- previous-line-length before-cursor, d
right:num <- get *editor, right:offset
width:num <- subtract right, left
wrap?:bool <- greater-than end-of-line, width
{
break-unless wrap?
_, column-offset:num <- divide-with-remainder end-of-line, width
cursor-column <- add left, column-offset
*editor <- put *editor, cursor-column:offset, cursor-column
}
{
break-if wrap?
cursor-column <- add left, end-of-line
*editor <- put *editor, cursor-column:offset, cursor-column
}
return
}
# case 2: if previous-character was not newline, we're just at a wrapped line
trace 10, [app], [wrapping to previous line]
right:num <- get *editor, right:offset
cursor-column <- subtract right, 1 # leave room for wrap icon
*editor <- put *editor, cursor-column:offset, cursor-column
]
# takes a pointer 'curr' into the doubly-linked list and its sentinel, counts
# the length of the previous line before the 'curr' pointer.
def previous-line-length curr:&:duplex-list:char, start:&:duplex-list:char -> result:num [
local-scope
load-inputs
result:num <- copy 0
return-unless curr
at-start?:bool <- equal curr, start
return-if at-start?
{
curr <- prev curr
break-unless curr
at-start?:bool <- equal curr, start
break-if at-start?
c:char <- get *curr, value:offset
at-newline?:bool <- equal c, 10/newline
break-if at-newline?
result <- add result, 1
loop
}
]
scenario editor-clears-last-line-on-backspace [
local-scope
assume-screen 10/width, 5/height
s:text <- new [ab
cd]
e:&:editor <- new-editor s, 0/left, 10/right
assume-console [
left-click 2, 0
press backspace
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.abcd .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
memory-should-contain [
4 <- 1
5 <- 2
]
]
scenario editor-joins-and-wraps-lines-on-backspace [
local-scope
assume-screen 10/width, 5/height
# initialize editor with two long-ish but non-wrapping lines
s:text <- new [abc def
ghi jkl]
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
assume-console [
left-click 2, 0
press backspace
]
run [
editor-event-loop screen, console, e
]
# resulting single line should wrap correctly
screen-should-contain [
. .
.abc defgh↩.
.i jkl .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
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], 0/left, 8/right
editor-render screen, e
# confirm that it wraps
screen-should-contain [
. .
.abc def↩ .
. ghij .
.┈┈┈┈┈┈┈┈ .
]
$clear-trace
# position the cursor somewhere in the middle of the top screen line and hit backspace
assume-console [
left-click 1, 4
press backspace
]
run [
editor-event-loop screen, console, e
]
# resulting single line should wrap correctly and not overflow its bounds
screen-should-contain [
. .
.abcdef ↩ .
.ghij .
.┈┈┈┈┈┈┈┈ .
. .
]
]
# delete - delete character at cursor
scenario editor-handles-delete-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
press delete
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 3, [print-character] # length of original line to overwrite
$clear-trace
assume-console [
press delete
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.c .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 2, [print-character] # new length to overwrite
]
after <handle-special-key> [
{
delete-next-character?:bool <- equal k, 65522/delete
break-unless delete-next-character?
<begin-delete-character>
go-render?:bool, deleted-cell:&:duplex-list:char <- delete-at-cursor editor, screen
<end-delete-character>
return
}
]
def delete-at-cursor editor:&:editor, screen:&:screen -> go-render?:bool, deleted-cell:&:duplex-list:char, editor:&:editor, screen:&:screen [
local-scope
load-inputs
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
data:&:duplex-list:char <- get *editor, data:offset
deleted-cell:&:duplex-list:char <- next before-cursor
return-unless deleted-cell, false/don't-render
currc:char <- get *deleted-cell, value:offset
data <- remove deleted-cell, data
deleted-newline?:bool <- equal currc, 10/newline
return-if deleted-newline?, true/go-render
# wasn't a newline? render rest of line
curr:&:duplex-list:char <- next before-cursor # refresh after remove above
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
screen <- move-cursor screen, cursor-row, cursor-column
curr-column:num <- copy cursor-column
screen-width:num <- screen-width screen
{
# hit right margin? give up and let caller render
at-right?:bool <- greater-or-equal curr-column, screen-width
return-if at-right?, true/go-render
break-unless curr
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
screen <- print screen, currc
curr-column <- add curr-column, 1
curr <- next curr
loop
}
# we're guaranteed not to be at the right margin
space:char <- copy 32/space
screen <- print screen, space
go-render? <- copy false
]
# right arrow
scenario editor-moves-cursor-right-with-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
press right-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.a0bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 3, [print-character] # 0 and following characters
]
after <handle-special-key> [
{
move-to-next-character?:bool <- equal k, 65514/right-arrow
break-unless move-to-next-character?
# if not at end of text
next-cursor:&:duplex-list:char <- next before-cursor
break-unless next-cursor
# scan to next character
<begin-move-cursor>
before-cursor <- copy next-cursor
*editor <- put *editor, before-cursor:offset, before-cursor
go-render?:bool <- move-cursor-coordinates-right editor, screen-height
screen <- move-cursor screen, cursor-row, cursor-column
undo-coalesce-tag:num <- copy 2/right-arrow
<end-move-cursor>
return
}
]
def move-cursor-coordinates-right editor:&:editor, screen-height:num -> go-render?:bool, editor:&:editor [
local-scope
load-inputs
before-cursor:&:duplex-list:char <- get *editor before-cursor:offset
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
# if crossed a newline, move cursor to start of next row
{
old-cursor-character:char <- get *before-cursor, value:offset
was-at-newline?:bool <- equal old-cursor-character, 10/newline
break-unless was-at-newline?
cursor-row <- add cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
below-screen?:bool <- greater-or-equal cursor-row, screen-height # must be equal
return-unless below-screen?, false/don't-render
cursor-row <- subtract cursor-row, 1 # bring back into screen range
*editor <- put *editor, cursor-row:offset, cursor-row
return true/go-render
}
# if the line wraps, move cursor to start of next row
{
# if we're at the column just before the wrap indicator
wrap-column:num <- subtract right, 1
at-wrap?:bool <- equal cursor-column, wrap-column
break-unless at-wrap?
# and if next character isn't newline
next:&:duplex-list:char <- next before-cursor
break-unless next
next-character:char <- get *next, value:offset
newline?:bool <- equal next-character, 10/newline
break-if newline?
cursor-row <- add cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
below-screen?:bool <- greater-or-equal cursor-row, screen-height # must be equal
return-unless below-screen?, false/no-more-render
cursor-row <- subtract cursor-row, 1 # bring back into screen range
*editor <- put *editor, cursor-row:offset, cursor-row
return true/go-render
}
# otherwise move cursor one character right
cursor-column <- add cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
go-render? <- copy false
]
scenario editor-moves-cursor-to-next-line-with-right-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
d]
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
assume-console [
press right-arrow
press right-arrow
press right-arrow
press right-arrow # next line
]
run [
editor-event-loop screen, console, e
]
check-trace-count-for-label 0, [print-character]
# type something and ensure it goes where it should
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0d .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 2, [print-character] # new length of second line
]
scenario editor-moves-cursor-to-next-line-with-right-arrow-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
d]
e:&:editor <- new-editor s, 1/left, 10/right
editor-render screen, e
assume-console [
press right-arrow
press right-arrow
press right-arrow
press right-arrow # next line
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. abc .
. 0d .
. ┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abcdef], 0/left, 5/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 3
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.abcd↩ .
.ef .
.┈┈┈┈┈ .
. .
]
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
]
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], 0/left, 5/right
editor-render screen, e
$clear-trace
# position cursor at last character before wrap and hit right-arrow
assume-console [
left-click 1, 3
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 0
]
# now hit right arrow again
assume-console [
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 1
]
check-trace-count-for-label 0, [print-character]
]
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], 1/left, 6/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 4
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
. abcd↩ .
. ef .
. ┈┈┈┈┈ .
. .
]
memory-should-contain [
3 <- 2
4 <- 1
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-cursor-to-next-line-with-right-arrow-at-end-of-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
d]
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
assume-console [
left-click 1, 3
press right-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
# new character should be in next line
screen-should-contain [
. .
.abc .
.0d .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 2, [print-character]
]
# todo: ctrl-right: next word-end
# left arrow
scenario editor-moves-cursor-left-with-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 2
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.a0bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 3, [print-character]
]
after <handle-special-key> [
{
move-to-previous-character?:bool <- equal k, 65515/left-arrow
break-unless move-to-previous-character?
trace 10, [app], [left arrow]
# if not at start of text (before-cursor at § sentinel)
prev:&:duplex-list:char <- prev before-cursor
return-unless prev, false/don't-render
<begin-move-cursor>
move-cursor-coordinates-left editor
before-cursor <- copy prev
*editor <- put *editor, before-cursor:offset, before-cursor
undo-coalesce-tag:num <- copy 1/left-arrow
<end-move-cursor>
return
}
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line [
local-scope
assume-screen 10/width, 5/height
# initialize editor with two lines
s:text <- new [abc
d]
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)
assume-console [
left-click 2, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-2 [
local-scope
assume-screen 10/width, 5/height
# initialize editor with three lines
s:text <- new [abc
def
g]
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
# the cursor)
assume-console [
left-click 3, 0
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.def0 .
.g .
.┈┈┈┈┈┈┈┈┈┈.
]
check-trace-count-for-label 1, [print-character] # just the '0'
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-3 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
def
g]
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
assume-console [
left-click 1, 0
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
# left-arrow should have had no effect
screen-should-contain [
. .
.0abc .
.def .
.g .
.┈┈┈┈┈┈┈┈┈┈.
]
check-trace-count-for-label 4, [print-character] # length of first line
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-4 [
local-scope
assume-screen 10/width, 5/height
# initialize editor with text containing an empty line
s:text <- new [abc
d]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e:&:editor
$clear-trace
# position cursor right after empty line
assume-console [
left-click 3, 0
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0 .
.d .
.┈┈┈┈┈┈┈┈┈┈.
]
check-trace-count-for-label 1, [print-character] # just the '0'
]
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], 0/left, 5/right
editor-render screen, e
$clear-trace
screen-should-contain [
. .
.abcd↩ .
.ef .
.┈┈┈┈┈ .
. .
]
# position cursor right after empty line
assume-console [
left-click 2, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1 # previous row
4 <- 3 # right margin except wrap icon
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-across-screen-lines-to-wrapping-line-with-left-arrow [
local-scope
assume-screen 10/width, 5/height
# initialize editor with a wrapping line followed by a second line
s:text <- new [abcdef
g]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
$clear-trace
screen-should-contain [
. .
.abcd↩ .
.ef .
.g .
.┈┈┈┈┈ .
]
# position cursor right after empty line
assume-console [
left-click 3, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2 # previous row
4 <- 2 # end of wrapped line
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-across-screen-lines-to-non-wrapping-line-with-left-arrow [
local-scope
assume-screen 10/width, 5/height
# 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, 0/left, 5/right
editor-render screen, e
$clear-trace
screen-should-contain [
. .
.abcd .
.e .
.┈┈┈┈┈ .
. .
]
# position cursor right after empty line
assume-console [
left-click 2, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1 # previous row
4 <- 4 # end of wrapped line
]
check-trace-count-for-label 0, [print-character]
]
# todo: ctrl-left: previous word-start
# up arrow
scenario editor-moves-to-previous-line-with-up-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
def]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 2, 1
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 1
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.a0bc .
.def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
after <handle-special-key> [
{
move-to-previous-line?:bool <- equal k, 65517/up-arrow
break-unless move-to-previous-line?
<begin-move-cursor>
move-to-previous-line editor
undo-coalesce-tag:num <- copy 3/up-arrow
<end-move-cursor>
return
}
]
def move-to-previous-line editor:&:editor -> editor:&:editor [
local-scope
load-inputs
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
already-at-top?:bool <- lesser-or-equal cursor-row, 1/top
{
# if cursor not at top, move it
break-if already-at-top?
# if not at newline, move to start of line (previous newline)
# then scan back another line
# if either step fails, give up without modifying cursor or coordinates
curr:&:duplex-list:char <- copy before-cursor
old:&:duplex-list:char <- copy curr
{
at-left?:bool <- equal cursor-column, left
break-if at-left?
curr <- before-previous-screen-line curr, editor
no-motion?:bool <- equal curr, old
return-if no-motion?
}
{
curr <- before-previous-screen-line curr, editor
no-motion?:bool <- equal curr, old
return-if no-motion?
}
before-cursor <- copy curr
*editor <- put *editor, before-cursor:offset, before-cursor
cursor-row <- subtract cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
# scan ahead to right column or until end of line
target-column:num <- copy cursor-column
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
{
done?:bool <- greater-or-equal cursor-column, target-column
break-if done?
curr:&:duplex-list:char <- next before-cursor
break-unless curr
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
#
before-cursor <- copy curr
*editor <- put *editor, before-cursor:offset, before-cursor
cursor-column <- add cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
loop
}
}
]
# Takes a pointer into the doubly-linked list, scans back to before start of
# previous *wrapped* line.
# Returns original if no next newline.
# Beware: never return null pointer.
def before-previous-screen-line in:&:duplex-list:char, editor:&:editor -> out:&:duplex-list:char [
local-scope
load-inputs
curr:&:duplex-list:char <- copy in
c:char <- get *curr, value:offset
# compute max, number of characters to skip
# 1 + len%(width-1)
# except rotate second term to vary from 1 to width-1 rather than 0 to width-2
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
max-line-length:num <- subtract right, left, -1/exclusive-right, 1/wrap-icon
sentinel:&:duplex-list:char <- get *editor, data:offset
len:num <- previous-line-length curr, sentinel
{
break-if len
# empty line; just skip this newline
prev:&:duplex-list:char <- prev curr
return-unless prev, curr
return prev
}
_, max:num <- divide-with-remainder len, max-line-length
# remainder 0 => scan one width-worth
{
break-if max
max <- copy max-line-length
}
max <- add max, 1
count:num <- copy 0
# skip 'max' characters
{
done?:bool <- greater-or-equal count, max
break-if done?
prev:&:duplex-list:char <- prev curr
break-unless prev
curr <- copy prev
count <- add count, 1
loop
}
return curr
]
scenario editor-adjusts-column-at-previous-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [ab
def]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 2, 3
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 2
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.ab0 .
.def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-adjusts-column-at-empty-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [
def]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 2, 3
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.0 .
.def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-moves-to-previous-line-from-zero-margin [
local-scope
assume-screen 10/width, 5/height
# start out with three lines
s:text <- new [abc
def
ghi]
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
assume-console [
left-click 3, 0
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0def .
.ghi .
.┈┈┈┈┈┈┈┈┈┈.
]
]
scenario editor-moves-to-previous-line-from-left-margin [
local-scope
assume-screen 10/width, 5/height
# start out with three lines
s:text <- new [abc
def
ghi]
e:&:editor <- new-editor s, 1/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
assume-console [
left-click 3, 1
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 1
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. abc .
. 0def .
. ghi .
. ┈┈┈┈┈┈┈┈┈.
]
]
scenario editor-moves-to-top-line-in-presence-of-wrapped-line [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abcde], 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.abcd↩ .
.e .
.┈┈┈┈┈ .
]
$clear-trace
assume-console [
left-click 2, 0
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.0abc↩ .
.de .
.┈┈┈┈┈ .
]
]
scenario editor-moves-to-top-line-in-presence-of-wrapped-line-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
defgh]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.abc .
.defg↩ .
.h .
.┈┈┈┈┈ .
]
$clear-trace
assume-console [
left-click 3, 0
press up-arrow
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.0abc .
.defg↩ .
.h .
.┈┈┈┈┈ .
]
]
# down arrow
scenario editor-moves-to-next-line-with-down-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
def]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# cursor starts out at (1, 0)
assume-console [
press down-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# ..and ends at (2, 0)
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
after <handle-special-key> [
{
move-to-next-line?:bool <- equal k, 65516/down-arrow
break-unless move-to-next-line?
<begin-move-cursor>
move-to-next-line editor, screen-height
undo-coalesce-tag:num <- copy 4/down-arrow
<end-move-cursor>
return
}
]
def move-to-next-line editor:&:editor, screen-height:num -> editor:&:editor [
local-scope
load-inputs
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
last-line:num <- subtract screen-height, 1
bottom:num <- get *editor, bottom:offset
at-bottom-of-screen?:bool <- greater-or-equal bottom, last-line
return-unless before-cursor
next:&:duplex-list:char <- next before-cursor
return-unless next
already-at-bottom?:bool <- greater-or-equal cursor-row, last-line
# if cursor not at bottom, move it
return-if already-at-bottom?
target-column:num <- copy cursor-column
# scan to start of next line
{
next:&:duplex-list:char <- next before-cursor
break-unless next
done?:bool <- greater-or-equal cursor-column, right
break-if done?
cursor-column <- add cursor-column, 1
before-cursor <- copy next
c:char <- get *next, value:offset
at-newline?:bool <- equal c, 10/newline
break-if at-newline?
loop
}
return-unless next
cursor-row <- add cursor-row, 1
cursor-column <- copy left
{
next:&:duplex-list:char <- next before-cursor
break-unless next
c:char <- get *next, value:offset
at-newline?:bool <- equal c, 10/newline
break-if at-newline?
done?:bool <- greater-or-equal cursor-column, target-column
break-if done?
cursor-column <- add cursor-column, 1
before-cursor <- copy next
loop
}
*editor <- put *editor, before-cursor:offset, before-cursor
*editor <- put *editor, cursor-column:offset, cursor-column
*editor <- put *editor, cursor-row:offset, cursor-row
]
scenario editor-adjusts-column-at-next-line [
local-scope
assume-screen 10/width, 5/height
# second line is shorter than first
s:text <- new [abcde
fg
hi]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# move to end of first line, then press down
assume-console [
left-click 1, 8
press down-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor doesn't go vertically down, it goes to end of shorter line
memory-should-contain [
3 <- 2
4 <- 2
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abcde .
.fg0 .
.hi .
.┈┈┈┈┈┈┈┈┈┈.
]
]
# ctrl-a/home - move cursor to start of line
scenario editor-moves-to-start-of-line-with-ctrl-a [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line, press ctrl-a
assume-console [
left-click 2, 3
press ctrl-a
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
4 <- 2
5 <- 0
]
check-trace-count-for-label 0, [print-character]
]
after <handle-special-character> [
{
move-to-start-of-line?:bool <- equal c, 1/ctrl-a
break-unless move-to-start-of-line?
<begin-move-cursor>
move-to-start-of-screen-line editor
undo-coalesce-tag:num <- copy 0/never
<end-move-cursor>
return false/don't-render
}
]
after <handle-special-key> [
{
move-to-start-of-line?:bool <- equal k, 65521/home
break-unless move-to-start-of-line?
<begin-move-cursor>
move-to-start-of-screen-line editor
undo-coalesce-tag:num <- copy 0/never
<end-move-cursor>
return false/don't-render
}
]
# handles wrapped lines
# precondition: cursor-column should be in a consistent state
def move-to-start-of-screen-line editor:&:editor -> editor:&:editor [
local-scope
load-inputs
# update cursor column
left:num <- get *editor, left:offset
col:num <- get *editor, cursor-column:offset
# update before-cursor
curr:&:duplex-list:char <- get *editor, before-cursor:offset
# while not at start of line, move
{
done?:bool <- equal col, left
break-if done?
assert curr, [move-to-start-of-line tried to move before start of text]
curr <- prev curr
col <- subtract col, 1
loop
}
*editor <- put *editor, cursor-column:offset, col
*editor <- put *editor, before-cursor:offset, curr
]
scenario editor-moves-to-start-of-line-with-ctrl-a-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
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
assume-console [
left-click 1, 3
press ctrl-a
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
4 <- 1
5 <- 0
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-start-of-line-with-home [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
$clear-trace
# start on second line, press 'home'
assume-console [
left-click 2, 3
press home
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-start-of-line-with-home-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line (no newline before), press 'home'
assume-console [
left-click 1, 3
press home
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
3 <- 1
4 <- 0
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-start-of-screen-line-with-ctrl-a [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [123456], 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.1234↩ .
.56 .
.┈┈┈┈┈ .
. .
]
$clear-trace
# start on second line, press ctrl-a then up
assume-console [
left-click 2, 1
press ctrl-a
press up-arrow
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of first line
memory-should-contain [
4 <- 1 # cursor-row
5 <- 0 # cursor-column
]
check-trace-count-for-label 0, [print-character]
# make sure before-cursor is in sync
assume-console [
type [a]
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.a123↩ .
.456 .
.┈┈┈┈┈ .
. .
]
memory-should-contain [
4 <- 1 # cursor-row
5 <- 1 # cursor-column
]
]
# ctrl-e/end - move cursor to end of line
scenario editor-moves-to-end-of-line-with-ctrl-e [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line, press ctrl-e
assume-console [
left-click 1, 1
press ctrl-e
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
4 <- 1
5 <- 3
]
check-trace-count-for-label 0, [print-character]
# editor inserts future characters at cursor
assume-console [
type [z]
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
4 <- 1
5 <- 4
]
screen-should-contain [
. .
.123z .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 1, [print-character]
]
after <handle-special-character> [
{
move-to-end-of-line?:bool <- equal c, 5/ctrl-e
break-unless move-to-end-of-line?
<begin-move-cursor>
move-to-end-of-line editor
undo-coalesce-tag:num <- copy 0/never
<end-move-cursor>
return false/don't-render
}
]
after <handle-special-key> [
{
move-to-end-of-line?:bool <- equal k, 65520/end
break-unless move-to-end-of-line?
<begin-move-cursor>
move-to-end-of-line editor
undo-coalesce-tag:num <- copy 0/never
<end-move-cursor>
return false/don't-render
}
]
def move-to-end-of-line editor:&:editor -> editor:&:editor [
local-scope
load-inputs
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
cursor-column:num <- get *editor, cursor-column:offset
right:num <- get *editor, right:offset
# while not at end of line, move
{
next:&:duplex-list:char <- next before-cursor
break-unless next # end of text
nextc:char <- get *next, value:offset
at-end-of-line?:bool <- equal nextc, 10/newline
break-if at-end-of-line?
cursor-column <- add cursor-column, 1
at-right?:bool <- equal cursor-column, right
break-if at-right?
*editor <- put *editor, cursor-column:offset, cursor-column
before-cursor <- copy next
*editor <- put *editor, before-cursor:offset, before-cursor
loop
}
]
scenario editor-moves-to-end-of-line-with-ctrl-e-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
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
assume-console [
left-click 2, 1
press ctrl-e
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
4 <- 2
5 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-end-of-line-with-end [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line, press 'end'
assume-console [
left-click 1, 1
press end
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
3 <- 1
4 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-end-of-line-with-end-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line (no newline after), press 'end'
assume-console [
left-click 2, 1
press end
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
3 <- 2
4 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-end-of-wrapped-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123456
789]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
$clear-trace
# start on first line, press 'end'
assume-console [
left-click 1, 1
press end
]
run [
editor-event-loop screen, console, e
10:num/raw <- get *e, cursor-row:offset
11:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
10 <- 1
11 <- 3
]
# no prints
check-trace-count-for-label 0, [print-character]
# before-cursor is also consistent
assume-console [
type [a]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.123a↩ .
.456 .
.789 .
.┈┈┈┈┈ .
]
]
# ctrl-u - delete text from start of line until (but not at) cursor
scenario editor-deletes-to-start-of-line-with-ctrl-u [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line, press ctrl-u
assume-console [
left-click 2, 2
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
.123 .
.6 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 10, [print-character]
]
after <handle-special-character> [
{
delete-to-start-of-line?:bool <- equal c, 21/ctrl-u
break-unless delete-to-start-of-line?
<begin-delete-to-start-of-line>
deleted-cells:&:duplex-list:char <- delete-to-start-of-line editor
<end-delete-to-start-of-line>
go-render?:bool <- minimal-render-for-ctrl-u screen, editor, deleted-cells
return
}
]
def minimal-render-for-ctrl-u screen:&:screen, editor:&:editor, deleted-cells:&:duplex-list:char -> go-render?:bool, screen:&:screen [
local-scope
load-inputs
curr-column:num <- get *editor, cursor-column:offset
# accumulate the current line as text and render it
buf:&:buffer:char <- new-buffer 30 # accumulator for the text we need to render
curr:&:duplex-list:char <- get *editor, before-cursor:offset
i:num <- copy curr-column
right:num <- get *editor, right:offset
{
# if we have a wrapped line, give up and render the whole screen
wrap?:bool <- greater-or-equal i, right
return-if wrap?, true/go-render
curr <- next curr
break-unless curr
c:char <- get *curr, value:offset
b:bool <- equal c, 10
break-if b
buf <- append buf, c
i <- add i, 1
loop
}
# if the line used to be wrapped, give up and render the whole screen
num-deleted-cells:num <- length deleted-cells
old-row-len:num <- add i, num-deleted-cells
left:num <- get *editor, left:offset
end:num <- subtract right, left
wrap?:bool <- greater-or-equal old-row-len, end
return-if wrap?, true/go-render
curr-line:text <- buffer-to-array buf
curr-row:num <- get *editor, cursor-row:offset
render-code screen, curr-line, curr-column, right, curr-row
return false/dont-render
]
def delete-to-start-of-line editor:&:editor -> result:&:duplex-list:char, editor:&:editor [
local-scope
load-inputs
# compute range to delete
init:&:duplex-list:char <- get *editor, data:offset
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
start:&:duplex-list:char <- copy before-cursor
end:&:duplex-list:char <- next before-cursor
{
at-start-of-text?:bool <- equal start, init
break-if at-start-of-text?
curr:char <- get *start, value:offset
at-start-of-line?:bool <- equal curr, 10/newline
break-if at-start-of-line?
start <- prev start
assert start, [delete-to-start-of-line tried to move before start of text]
loop
}
# snip it out
result:&:duplex-list:char <- next start
remove-between start, end
# adjust cursor
before-cursor <- copy start
*editor <- put *editor, before-cursor:offset, before-cursor
left:num <- get *editor, left:offset
*editor <- put *editor, cursor-column:offset, left
# if the line wrapped before, we may need to adjust cursor-row as well
right:num <- get *editor, right:offset
width:num <- subtract right, left
num-deleted:num <- length result
cursor-row-adjustment:num <- divide-with-remainder num-deleted, width
return-unless cursor-row-adjustment
cursor-row:num <- get *editor, cursor-row:offset
cursor-row <- subtract cursor-row, cursor-row-adjustment
put *editor, cursor-row:offset, cursor-row
]
def render-code screen:&:screen, s:text, left:num, right:num, row:num -> row:num, screen:&:screen [
local-scope
load-inputs
return-unless s
color:num <- copy 7/white
column:num <- copy left
screen <- move-cursor screen, row, column
screen-height:num <- screen-height screen
i:num <- copy 0
len:num <- length *s
{
+next-character
done?:bool <- greater-or-equal i, len
break-if done?
done? <- greater-or-equal row, screen-height
break-if done?
c:char <- index *s, i
<character-c-received>
{
# newline? move to left rather than 0
newline?:bool <- equal c, 10/newline
break-unless newline?
# clear rest of line in this window
{
done?:bool <- greater-than column, right
break-if done?
space:char <- copy 32/space
print screen, space
column <- add column, 1
loop
}
row <- add row, 1
column <- copy left
screen <- move-cursor screen, row, column
i <- add i, 1
loop +next-character
}
{
# at right? wrap.
at-right?:bool <- equal column, right
break-unless at-right?
# print wrap icon
wrap-icon:char <- copy 8617/loop-back-to-left
print screen, wrap-icon, 245/grey
column <- copy left
row <- add row, 1
screen <- move-cursor screen, row, column
# don't increment i
loop +next-character
}
i <- add i, 1
print screen, c, color
column <- add column, 1
loop
}
was-at-left?:bool <- equal column, left
clear-line-until screen, right
{
break-if was-at-left?
row <- add row, 1
}
move-cursor screen, row, left
]
scenario editor-deletes-to-start-of-line-with-ctrl-u-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line (no newline before), press ctrl-u
assume-console [
left-click 1, 2
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
.3 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 10, [print-character]
]
scenario editor-deletes-to-start-of-line-with-ctrl-u-3 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start past end of line, press ctrl-u
assume-console [
left-click 1, 3
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
. .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 10, [print-character]
]
scenario editor-deletes-to-start-of-final-line-with-ctrl-u [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start past end of final line, press ctrl-u
assume-console [
left-click 2, 3
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
.123 .
. .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 10, [print-character]
]
scenario editor-deletes-to-start-of-wrapped-line-with-ctrl-u [
local-scope
assume-screen 10/width, 10/height
# first line starts out wrapping
s:text <- new [123456
789]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.1234↩ .
.56 .
.789 .
.┈┈┈┈┈ .
. .
]
$clear-trace
# ctrl-u enough of the first line that it's no longer wrapping
assume-console [
left-click 1, 3
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# entire screen needs to be refreshed
screen-should-contain [
. .
.456 .
.789 .
.┈┈┈┈┈ .
. .
]
check-trace-count-for-label 45, [print-character]
]
# sometimes hitting ctrl-u needs to adjust the cursor row
scenario editor-deletes-to-start-of-wrapped-line-with-ctrl-u-2 [
local-scope
assume-screen 10/width, 10/height
# third line starts out wrapping
s:text <- new [1
2
345678
9]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.1 .
.2 .
.3456↩ .
.78 .
.9 .
.┈┈┈┈┈ .
. .
]
# position cursor on screen line after the wrap and hit ctrl-u
assume-console [
left-click 4, 1 # on '8'
press ctrl-u
]
run [
editor-event-loop screen, console, e
10:num/raw <- get *e, cursor-row:offset
11:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.1 .
.2 .
.8 .
.9 .
.┈┈┈┈┈ .
. .
]
# cursor moves up one screen line
memory-should-contain [
10 <- 3 # cursor-row
11 <- 0 # cursor-column
]
]
# line wrapping twice (taking up 3 screen lines)
scenario editor-deletes-to-start-of-wrapped-line-with-ctrl-u-3 [
local-scope
assume-screen 10/width, 10/height
# third line starts out wrapping
s:text <- new [1
2
3456789abcd
e]
e:&:editor <- new-editor s, 0/left, 5/right
editor-render screen, e
assume-console [
left-click 4, 1 # on '8'
]
editor-event-loop screen, console, e
screen-should-contain [
. .
.1 .
.2 .
.3456↩ .
.789a↩ .
.bcd .
.e .
.┈┈┈┈┈ .
. .
]
assume-console [
left-click 5, 1
press ctrl-u
]
run [
editor-event-loop screen, console, e
10:num/raw <- get *e, cursor-row:offset
11:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.1 .
.2 .
.cd .
.e .
.┈┈┈┈┈ .
. .
]
# make sure we adjusted cursor-row
memory-should-contain [
10 <- 3 # cursor-row
11 <- 0 # cursor-column
]
]
# ctrl-k - delete text from cursor to end of line (but not the newline)
scenario editor-deletes-to-end-of-line-with-ctrl-k [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line, press ctrl-k
assume-console [
left-click 1, 1
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to end of line
screen-should-contain [
. .
.1 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 9, [print-character]
]
after <handle-special-character> [
{
delete-to-end-of-line?:bool <- equal c, 11/ctrl-k
break-unless delete-to-end-of-line?
<begin-delete-to-end-of-line>
deleted-cells:&:duplex-list:char <- delete-to-end-of-line editor
<end-delete-to-end-of-line>
# checks if we can do a minimal render and if we can it will do a minimal render
go-render?:bool <- minimal-render-for-ctrl-k screen, editor, deleted-cells
return
}
]
def minimal-render-for-ctrl-k screen:&:screen, editor:&:editor, deleted-cells:&:duplex-list:char -> go-render?:bool, screen:&:screen [
local-scope
load-inputs
# if we deleted nothing, there's nothing to render
return-unless deleted-cells, false/dont-render
# if the line used to wrap before, give up and render the whole screen
curr-column:num <- get *editor, cursor-column:offset
num-deleted-cells:num <- length deleted-cells
old-row-len:num <- add curr-column, num-deleted-cells
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
end:num <- subtract right, left
wrap?:bool <- greater-or-equal old-row-len, end
return-if wrap?, true/go-render
clear-line-until screen, right
return false/dont-render
]
def delete-to-end-of-line editor:&:editor -> result:&:duplex-list:char, editor:&:editor [
local-scope
load-inputs
# compute range to delete
start:&:duplex-list:char <- get *editor, before-cursor:offset
end:&:duplex-list:char <- next start
{
at-end-of-text?:bool <- equal end, null
break-if at-end-of-text?
curr:char <- get *end, value:offset
at-end-of-line?:bool <- equal curr, 10/newline
break-if at-end-of-line?
end <- next end
loop
}
# snip it out
result <- next start
remove-between start, end
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line (no newline after), press ctrl-k
assume-console [
left-click 2, 1
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to end of line
screen-should-contain [
. .
.123 .
.4 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 9, [print-character]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-3 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start at end of line
assume-console [
left-click 1, 2
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes just last character
screen-should-contain [
. .
.12 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 8, [print-character]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-4 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start past end of line
assume-console [
left-click 1, 3
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes nothing
screen-should-contain [
. .
.123 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 7, [print-character]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-5 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start at end of text
assume-console [
left-click 2, 2
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes just the final character
screen-should-contain [
. .
.123 .
.45 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 8, [print-character]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-6 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, 0/left, 10/right
editor-render screen, e
$clear-trace
# start past end of text
assume-console [
left-click 2, 3
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes nothing
screen-should-contain [
. .
.123 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
# no prints necessary
check-trace-count-for-label 0, [print-character]
]
scenario editor-deletes-to-end-of-wrapped-line-with-ctrl-k [
local-scope
assume-screen 10/width, 5/height
# create an editor with the first line wrapping to a second screen row
s:text <- new [1234
567]
e:&:editor <- new-editor s, 0/left, 4/right
editor-render screen, e
$clear-trace
# delete all of the first wrapped line
assume-console [
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# screen shows an empty unwrapped first line
screen-should-contain [
. .
. .
.567 .
.┈┈┈┈ .
. .
]
# entire screen is refreshed
check-trace-count-for-label 16, [print-character]
]
# takes a pointer into the doubly-linked list, scans ahead at most 'max'
# positions until the next newline
# returns original if no next newline
# beware: never return null pointer.
def before-start-of-next-line original:&:duplex-list:char, max:num -> curr:&:duplex-list:char [
local-scope
load-inputs
count:num <- copy 0
curr:&:duplex-list:char <- copy original
# skip the initial newline if it exists
{
c:char <- get *curr, value:offset
at-newline?:bool <- equal c, 10/newline
break-unless at-newline?
curr <- next curr
count <- add count, 1
}
{
return-unless curr, original
done?:bool <- greater-or-equal count, max
break-if done?
c:char <- get *curr, value:offset
at-newline?:bool <- equal c, 10/newline
break-if at-newline?
curr <- next curr
count <- add count, 1
loop
}
return-unless curr, original
return curr
]
# ctrl-/ - comment/uncomment current line
after <handle-special-character> [
{
comment-toggle?:bool <- equal c, 31/ctrl-slash
break-unless comment-toggle?
cursor-column:num <- get *editor, cursor-column:offset
data:&:duplex-list:char <- get *editor, data:offset
<begin-insert-character>
before-line-start:&:duplex-list:char <- before-start-of-screen-line editor
line-start:&:duplex-list:char <- next before-line-start
commented-out?:bool <- match line-start, [#? ] # comment prefix
{
break-unless commented-out?
# uncomment
data <- remove line-start, 3/length-comment-prefix, data
cursor-column <- subtract cursor-column, 3/length-comment-prefix
*editor <- put *editor, cursor-column:offset, cursor-column
go-render? <- render-line-from-start screen, editor, 3/size-of-comment-leader
}
{
break-if commented-out?
# comment
insert before-line-start, [#? ]
cursor-column <- add cursor-column, 3/length-comment-prefix
*editor <- put *editor, cursor-column:offset, cursor-column
go-render? <- render-line-from-start screen, editor, 0
}
<end-insert-character>
return
}
]
# Render just from the start of the current line, and only if it wasn't
# wrapping before (include margin) and isn't wrapping now. Otherwise just tell
# the caller to go-render? the entire screen.
def render-line-from-start screen:&:screen, editor:&:editor, right-margin:num -> go-render?:bool, screen:&:screen [
local-scope
load-inputs
before-line-start:&:duplex-list:char <- before-start-of-screen-line editor
line-start:&:duplex-list:char <- next before-line-start
color:num <- copy 7/white
left:num <- get *editor, left:offset
cursor-row:num <- get *editor, cursor-row:offset
screen <- move-cursor screen, cursor-row, left
right:num <- get *editor, right:offset
end:num <- subtract right, right-margin
i:num <- copy 0
curr:&:duplex-list:char <- copy line-start
{
render-all?:bool <- greater-or-equal i, end
return-if render-all?, true/go-render
break-unless curr
c:char <- get *curr, value:offset
newline?:bool <- equal c, 10/newline
break-if newline?
color <- get-color color, c
print screen, c, color
curr <- next curr
i <- add i, 1
loop
}
clear-line-until screen, right
return false/dont-render
]
def before-start-of-screen-line editor:&:editor -> result:&:duplex-list:char [
local-scope
load-inputs
cursor:&:duplex-list:char <- get *editor, before-cursor:offset
{
next:&:duplex-list:char <- next cursor
break-unless next
cursor <- copy next
}
result <- before-previous-screen-line cursor, editor
]
scenario editor-comments-empty-line [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [], 0/left, 5/right
editor-render screen, e
$clear-trace
assume-console [
press ctrl-slash
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.#? .
.┈┈┈┈┈ .
. .
]
memory-should-contain [
4 <- 1
5 <- 3
]
check-trace-count-for-label 5, [print-character]
]
scenario editor-comments-at-start-of-contents [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [ab], 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
press ctrl-slash
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.#? ab .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
memory-should-contain [
4 <- 1
5 <- 3
]
check-trace-count-for-label 10, [print-character]
]
scenario editor-comments-at-end-of-contents [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [ab], 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 7
press ctrl-slash
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.#? ab .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
memory-should-contain [
4 <- 1
5 <- 5
]
check-trace-count-for-label 10, [print-character]
# toggle to uncomment
$clear-trace
assume-console [
press ctrl-slash
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.ab .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 10, [print-character]
]
scenario editor-comments-almost-wrapping-line [
local-scope
assume-screen 10/width, 5/height
# editor starts out with a non-wrapping line
e:&:editor <- new-editor [abcd], 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.abcd .
.┈┈┈┈┈ .
. .
]
$clear-trace
# on commenting the line is now wrapped
assume-console [
left-click 1, 7
press ctrl-slash
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.#? a↩ .
.bcd .
.┈┈┈┈┈ .
. .
]
]
scenario editor-uncomments-just-wrapping-line [
local-scope
assume-screen 10/width, 5/height
# editor starts out with a comment that wraps the line
e:&:editor <- new-editor [#? ab], 0/left, 5/right
editor-render screen, e
screen-should-contain [
. .
.#? a↩ .
.b .
.┈┈┈┈┈ .
. .
]
$clear-trace
# on uncommenting the line is no longer wrapped
assume-console [
left-click 1, 7
press ctrl-slash
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.ab .
.┈┈┈┈┈ .
. .
]
]