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author | Kartik K. Agaram <vc@akkartik.com> | 2021-08-15 21:09:17 -0700 |
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committer | Kartik K. Agaram <vc@akkartik.com> | 2021-08-15 21:09:17 -0700 |
commit | 8765064d6910c65ea5ed5526b27e9752df000c3d (patch) | |
tree | 34d9e77438e284c9b6e2647aa7e57241e82cff89 /514gap-buffer.mu | |
parent | 412a68d0c1a3375f340344265cc3d71dfcfec887 (diff) | |
download | mu-8765064d6910c65ea5ed5526b27e9752df000c3d.tar.gz |
move gap buffer code to top-level
Now that it's been used in a second app without needing any changes.
Diffstat (limited to '514gap-buffer.mu')
-rw-r--r-- | 514gap-buffer.mu | 1470 |
1 files changed, 1470 insertions, 0 deletions
diff --git a/514gap-buffer.mu b/514gap-buffer.mu new file mode 100644 index 00000000..0077d6fd --- /dev/null +++ b/514gap-buffer.mu @@ -0,0 +1,1470 @@ +# primitive for editing text + +type gap-buffer { + left: grapheme-stack + right: grapheme-stack + # some fields for scanning incrementally through a gap-buffer + left-read-index: int + right-read-index: int +} + +fn initialize-gap-buffer _self: (addr gap-buffer), capacity: int { + var self/esi: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + initialize-grapheme-stack left, capacity + var right/eax: (addr grapheme-stack) <- get self, right + initialize-grapheme-stack right, capacity +} + +fn clear-gap-buffer _self: (addr gap-buffer) { + var self/esi: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + clear-grapheme-stack left + var right/eax: (addr grapheme-stack) <- get self, right + clear-grapheme-stack right +} + +fn gap-buffer-empty? _self: (addr gap-buffer) -> _/eax: boolean { + var self/esi: (addr gap-buffer) <- copy _self + # if !empty?(left) return false + { + var left/eax: (addr grapheme-stack) <- get self, left + var result/eax: boolean <- grapheme-stack-empty? left + compare result, 0/false + break-if-!= + return 0/false + } + # return empty?(right) + var left/eax: (addr grapheme-stack) <- get self, left + var result/eax: boolean <- grapheme-stack-empty? left + return result +} + +fn gap-buffer-capacity _gap: (addr gap-buffer) -> _/edx: int { + var gap/esi: (addr gap-buffer) <- copy _gap + var left/eax: (addr grapheme-stack) <- get gap, left + var left-data-ah/eax: (addr handle array grapheme) <- get left, data + var left-data/eax: (addr array grapheme) <- lookup *left-data-ah + var result/eax: int <- length left-data + return result +} + +# just for tests +fn initialize-gap-buffer-with self: (addr gap-buffer), keys: (addr array byte) { + initialize-gap-buffer self, 0x40/capacity + var input-stream-storage: (stream byte 0x40/capacity) + var input-stream/ecx: (addr stream byte) <- address input-stream-storage + write input-stream, keys + { + var done?/eax: boolean <- stream-empty? input-stream + compare done?, 0/false + break-if-!= + var g/eax: grapheme <- read-grapheme input-stream + add-grapheme-at-gap self, g + loop + } +} + +fn load-gap-buffer-from-stream self: (addr gap-buffer), in: (addr stream byte) { + rewind-stream in + { + var done?/eax: boolean <- stream-empty? in + compare done?, 0/false + break-if-!= + var key/eax: byte <- read-byte in + compare key, 0/null + break-if-= + var g/eax: grapheme <- copy key + edit-gap-buffer self, g + loop + } +} + +fn emit-gap-buffer self: (addr gap-buffer), out: (addr stream byte) { + clear-stream out + append-gap-buffer self, out +} + +fn append-gap-buffer _self: (addr gap-buffer), out: (addr stream byte) { + var self/esi: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + emit-stack-from-bottom left, out + var right/eax: (addr grapheme-stack) <- get self, right + emit-stack-from-top right, out +} + +# dump stack from bottom to top +fn emit-stack-from-bottom _self: (addr grapheme-stack), out: (addr stream byte) { + var self/esi: (addr grapheme-stack) <- copy _self + var data-ah/edi: (addr handle array grapheme) <- get self, data + var _data/eax: (addr array grapheme) <- lookup *data-ah + var data/edi: (addr array grapheme) <- copy _data + var top-addr/ecx: (addr int) <- get self, top + var i/eax: int <- copy 0 + { + compare i, *top-addr + break-if->= + var g/edx: (addr grapheme) <- index data, i + write-grapheme out, *g + i <- increment + loop + } +} + +# dump stack from top to bottom +fn emit-stack-from-top _self: (addr grapheme-stack), out: (addr stream byte) { + var self/esi: (addr grapheme-stack) <- copy _self + var data-ah/edi: (addr handle array grapheme) <- get self, data + var _data/eax: (addr array grapheme) <- lookup *data-ah + var data/edi: (addr array grapheme) <- copy _data + var top-addr/ecx: (addr int) <- get self, top + var i/eax: int <- copy *top-addr + i <- decrement + { + compare i, 0 + break-if-< + var g/edx: (addr grapheme) <- index data, i + write-grapheme out, *g + i <- decrement + loop + } +} + +fn word-at-gap _self: (addr gap-buffer), out: (addr stream byte) { + var self/esi: (addr gap-buffer) <- copy _self + clear-stream out + { + var g/eax: grapheme <- grapheme-at-gap self + var at-word?/eax: boolean <- is-ascii-word-grapheme? g + compare at-word?, 0/false + break-if-!= + return + } + var left/ecx: (addr grapheme-stack) <- get self, left + var left-index/eax: int <- top-most-word left + emit-stack-from-index left, left-index, out + var right/ecx: (addr grapheme-stack) <- get self, right + var right-index/eax: int <- top-most-word right + emit-stack-to-index right, right-index, out +} + +fn test-word-at-gap-single-word-with-gap-at-end { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "abc" + # gap is at end (right is empty) + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "abc", "F - test-word-at-gap-single-word-with-gap-at-end" +} + +fn test-word-at-gap-single-word-with-gap-at-start { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "abc" + gap-to-start g + # + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "abc", "F - test-word-at-gap-single-word-with-gap-at-start" +} + +fn test-word-at-gap-multiple-words-with-gap-at-non-word-grapheme-at-end { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "abc " + # gap is at end (right is empty) + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "", "F - test-word-at-gap-multiple-words-with-gap-at-non-word-grapheme-at-end" +} + +fn test-word-at-gap-multiple-words-with-gap-at-non-word-grapheme-at-start { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, " abc" + gap-to-start g + # + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "", "F - test-word-at-gap-multiple-words-with-gap-at-non-word-grapheme-at-start" +} + +fn test-word-at-gap-multiple-words-with-gap-at-end { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "a bc d" + # gap is at end (right is empty) + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "d", "F - test-word-at-gap-multiple-words-with-gap-at-end" +} + +fn test-word-at-gap-multiple-words-with-gap-at-initial-word { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "a bc d" + gap-to-start g + # + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "a", "F - test-word-at-gap-multiple-words-with-gap-at-initial-word" +} + +fn test-word-at-gap-multiple-words-with-gap-at-final-word { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "a bc d" + var dummy/eax: grapheme <- gap-left g + # gap is at final word + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "d", "F - test-word-at-gap-multiple-words-with-gap-at-final-word" +} + +fn test-word-at-gap-multiple-words-with-gap-at-final-non-word { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer-with g, "abc " + var dummy/eax: grapheme <- gap-left g + # gap is at final word + var out-storage: (stream byte 0x10) + var out/eax: (addr stream byte) <- address out-storage + word-at-gap g, out + check-stream-equal out, "", "F - test-word-at-gap-multiple-words-with-gap-at-final-non-word" +} + +fn grapheme-at-gap _self: (addr gap-buffer) -> _/eax: grapheme { + # send top of right most of the time + var self/esi: (addr gap-buffer) <- copy _self + var right/edi: (addr grapheme-stack) <- get self, right + var data-ah/eax: (addr handle array grapheme) <- get right, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var top-addr/ecx: (addr int) <- get right, top + { + compare *top-addr, 0 + break-if-<= + var top/ecx: int <- copy *top-addr + top <- decrement + var result/eax: (addr grapheme) <- index data, top + return *result + } + # send top of left only if right is empty + var left/edi: (addr grapheme-stack) <- get self, left + var data-ah/eax: (addr handle array grapheme) <- get left, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var top-addr/ecx: (addr int) <- get left, top + { + compare *top-addr, 0 + break-if-<= + var top/ecx: int <- copy *top-addr + top <- decrement + var result/eax: (addr grapheme) <- index data, top + return *result + } + # send null if everything is empty + return 0 +} + +fn top-most-word _self: (addr grapheme-stack) -> _/eax: int { + var self/esi: (addr grapheme-stack) <- copy _self + var data-ah/edi: (addr handle array grapheme) <- get self, data + var _data/eax: (addr array grapheme) <- lookup *data-ah + var data/edi: (addr array grapheme) <- copy _data + var top-addr/ecx: (addr int) <- get self, top + var i/ebx: int <- copy *top-addr + i <- decrement + { + compare i, 0 + break-if-< + var g/edx: (addr grapheme) <- index data, i + var is-word?/eax: boolean <- is-ascii-word-grapheme? *g + compare is-word?, 0/false + break-if-= + i <- decrement + loop + } + i <- increment + return i +} + +fn emit-stack-from-index _self: (addr grapheme-stack), start: int, out: (addr stream byte) { + var self/esi: (addr grapheme-stack) <- copy _self + var data-ah/edi: (addr handle array grapheme) <- get self, data + var _data/eax: (addr array grapheme) <- lookup *data-ah + var data/edi: (addr array grapheme) <- copy _data + var top-addr/ecx: (addr int) <- get self, top + var i/eax: int <- copy start + { + compare i, *top-addr + break-if->= + var g/edx: (addr grapheme) <- index data, i + write-grapheme out, *g + i <- increment + loop + } +} + +fn emit-stack-to-index _self: (addr grapheme-stack), end: int, out: (addr stream byte) { + var self/esi: (addr grapheme-stack) <- copy _self + var data-ah/edi: (addr handle array grapheme) <- get self, data + var _data/eax: (addr array grapheme) <- lookup *data-ah + var data/edi: (addr array grapheme) <- copy _data + var top-addr/ecx: (addr int) <- get self, top + var i/eax: int <- copy *top-addr + i <- decrement + { + compare i, 0 + break-if-< + compare i, end + break-if-< + var g/edx: (addr grapheme) <- index data, i + write-grapheme out, *g + i <- decrement + loop + } +} + +fn is-ascii-word-grapheme? g: grapheme -> _/eax: boolean { + compare g, 0x21/! + { + break-if-!= + return 1/true + } + compare g, 0x30/0 + { + break-if->= + return 0/false + } + compare g, 0x39/9 + { + break-if-> + return 1/true + } + compare g, 0x3f/? + { + break-if-!= + return 1/true + } + compare g, 0x41/A + { + break-if->= + return 0/false + } + compare g, 0x5a/Z + { + break-if-> + return 1/true + } + compare g, 0x5f/_ + { + break-if-!= + return 1/true + } + compare g, 0x61/a + { + break-if->= + return 0/false + } + compare g, 0x7a/z + { + break-if-> + return 1/true + } + return 0/false +} + +# We implicitly render everything editable in a single color, and assume the +# cursor is a single other color. +fn render-gap-buffer-wrapping-right-then-down screen: (addr screen), _gap: (addr gap-buffer), xmin: int, ymin: int, xmax: int, ymax: int, render-cursor?: boolean, color: int, background-color: int -> _/eax: int, _/ecx: int { + var gap/esi: (addr gap-buffer) <- copy _gap + var left/edx: (addr grapheme-stack) <- get gap, left + var highlight-matching-open-paren?/ebx: boolean <- copy 0/false + var matching-open-paren-depth/edi: int <- copy 0 + highlight-matching-open-paren?, matching-open-paren-depth <- highlight-matching-open-paren? gap, render-cursor? + var x2/eax: int <- copy 0 + var y2/ecx: int <- copy 0 + x2, y2 <- render-stack-from-bottom-wrapping-right-then-down screen, left, xmin, ymin, xmax, ymax, xmin, ymin, highlight-matching-open-paren?, matching-open-paren-depth, color, background-color + var right/edx: (addr grapheme-stack) <- get gap, right + x2, y2 <- render-stack-from-top-wrapping-right-then-down screen, right, xmin, ymin, xmax, ymax, x2, y2, render-cursor?, color, background-color + # decide whether we still need to print a cursor + var fg/edi: int <- copy color + var bg/ebx: int <- copy background-color + compare render-cursor?, 0/false + { + break-if-= + # if the right side is empty, grapheme stack didn't print the cursor + var empty?/eax: boolean <- grapheme-stack-empty? right + compare empty?, 0/false + break-if-= + # swap foreground and background + fg <- copy background-color + bg <- copy color + } + # print a grapheme either way so that cursor position doesn't affect printed width + var space/edx: grapheme <- copy 0x20 + x2, y2 <- render-grapheme screen, space, xmin, ymin, xmax, ymax, x2, y2, fg, bg + return x2, y2 +} + +fn render-gap-buffer screen: (addr screen), gap: (addr gap-buffer), x: int, y: int, render-cursor?: boolean, color: int, background-color: int -> _/eax: int { + var _width/eax: int <- copy 0 + var _height/ecx: int <- copy 0 + _width, _height <- screen-size screen + var width/edx: int <- copy _width + var height/ebx: int <- copy _height + var x2/eax: int <- copy 0 + var y2/ecx: int <- copy 0 + x2, y2 <- render-gap-buffer-wrapping-right-then-down screen, gap, x, y, width, height, render-cursor?, color, background-color + return x2 # y2? yolo +} + +fn gap-buffer-length _gap: (addr gap-buffer) -> _/eax: int { + var gap/esi: (addr gap-buffer) <- copy _gap + var left/eax: (addr grapheme-stack) <- get gap, left + var tmp/eax: (addr int) <- get left, top + var left-length/ecx: int <- copy *tmp + var right/esi: (addr grapheme-stack) <- get gap, right + tmp <- get right, top + var result/eax: int <- copy *tmp + result <- add left-length + return result +} + +fn add-grapheme-at-gap _self: (addr gap-buffer), g: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + push-grapheme-stack left, g +} + +fn add-code-point-at-gap self: (addr gap-buffer), c: code-point { + var g/eax: grapheme <- copy c + add-grapheme-at-gap self, g +} + +fn gap-to-start self: (addr gap-buffer) { + { + var curr/eax: grapheme <- gap-left self + compare curr, -1 + loop-if-!= + } +} + +fn gap-to-end self: (addr gap-buffer) { + { + var curr/eax: grapheme <- gap-right self + compare curr, -1 + loop-if-!= + } +} + +fn gap-at-start? _self: (addr gap-buffer) -> _/eax: boolean { + var self/esi: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + var result/eax: boolean <- grapheme-stack-empty? left + return result +} + +fn gap-at-end? _self: (addr gap-buffer) -> _/eax: boolean { + var self/esi: (addr gap-buffer) <- copy _self + var right/eax: (addr grapheme-stack) <- get self, right + var result/eax: boolean <- grapheme-stack-empty? right + return result +} + +fn gap-right _self: (addr gap-buffer) -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + var g/eax: grapheme <- copy 0 + var right/ecx: (addr grapheme-stack) <- get self, right + g <- pop-grapheme-stack right + compare g, -1 + { + break-if-= + var left/ecx: (addr grapheme-stack) <- get self, left + push-grapheme-stack left, g + } + return g +} + +fn gap-left _self: (addr gap-buffer) -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + var g/eax: grapheme <- copy 0 + { + var left/ecx: (addr grapheme-stack) <- get self, left + g <- pop-grapheme-stack left + } + compare g, -1 + { + break-if-= + var right/ecx: (addr grapheme-stack) <- get self, right + push-grapheme-stack right, g + } + return g +} + +fn index-of-gap _self: (addr gap-buffer) -> _/eax: int { + var self/eax: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + var top-addr/eax: (addr int) <- get left, top + var result/eax: int <- copy *top-addr + return result +} + +fn first-grapheme-in-gap-buffer _self: (addr gap-buffer) -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + # try to read from left + var left/eax: (addr grapheme-stack) <- get self, left + var top-addr/ecx: (addr int) <- get left, top + compare *top-addr, 0 + { + break-if-<= + var data-ah/eax: (addr handle array grapheme) <- get left, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var result-addr/eax: (addr grapheme) <- index data, 0 + return *result-addr + } + # try to read from right + var right/eax: (addr grapheme-stack) <- get self, right + top-addr <- get right, top + compare *top-addr, 0 + { + break-if-<= + var data-ah/eax: (addr handle array grapheme) <- get right, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var top/ecx: int <- copy *top-addr + top <- decrement + var result-addr/eax: (addr grapheme) <- index data, top + return *result-addr + } + # give up + return -1 +} + +fn grapheme-before-cursor-in-gap-buffer _self: (addr gap-buffer) -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + # try to read from left + var left/ecx: (addr grapheme-stack) <- get self, left + var top-addr/edx: (addr int) <- get left, top + compare *top-addr, 0 + { + break-if-<= + var result/eax: grapheme <- pop-grapheme-stack left + push-grapheme-stack left, result + return result + } + # give up + return -1 +} + +fn delete-before-gap _self: (addr gap-buffer) { + var self/eax: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + var dummy/eax: grapheme <- pop-grapheme-stack left +} + +fn pop-after-gap _self: (addr gap-buffer) -> _/eax: grapheme { + var self/eax: (addr gap-buffer) <- copy _self + var right/eax: (addr grapheme-stack) <- get self, right + var result/eax: grapheme <- pop-grapheme-stack right + return result +} + +fn gap-buffer-equal? _self: (addr gap-buffer), s: (addr array byte) -> _/eax: boolean { + var self/esi: (addr gap-buffer) <- copy _self + # complication: graphemes may be multiple bytes + # so don't rely on length + # instead turn the expected result into a stream and arrange to read from it in order + var stream-storage: (stream byte 0x10/capacity) + var expected-stream/ecx: (addr stream byte) <- address stream-storage + write expected-stream, s + # compare left + var left/edx: (addr grapheme-stack) <- get self, left + var result/eax: boolean <- prefix-match? left, expected-stream + compare result, 0/false + { + break-if-!= + return result + } + # compare right + var right/edx: (addr grapheme-stack) <- get self, right + result <- suffix-match? right, expected-stream + compare result, 0/false + { + break-if-!= + return result + } + # ensure there's nothing left over + result <- stream-empty? expected-stream + return result +} + +fn test-gap-buffer-equal-from-end { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer g, 0x10 + # + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + # gap is at end (right is empty) + var result/eax: boolean <- gap-buffer-equal? g, "aaa" + check result, "F - test-gap-buffer-equal-from-end" +} + +fn test-gap-buffer-equal-from-middle { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer g, 0x10 + # + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + var dummy/eax: grapheme <- gap-left g + # gap is in the middle + var result/eax: boolean <- gap-buffer-equal? g, "aaa" + check result, "F - test-gap-buffer-equal-from-middle" +} + +fn test-gap-buffer-equal-from-start { + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer g, 0x10 + # + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + var dummy/eax: grapheme <- gap-left g + dummy <- gap-left g + dummy <- gap-left g + # gap is at the start + var result/eax: boolean <- gap-buffer-equal? g, "aaa" + check result, "F - test-gap-buffer-equal-from-start" +} + +fn test-gap-buffer-equal-fails { + # g = "aaa" + var _g: gap-buffer + var g/esi: (addr gap-buffer) <- address _g + initialize-gap-buffer g, 0x10 + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + add-code-point-at-gap g, 0x61/a + # + var result/eax: boolean <- gap-buffer-equal? g, "aa" + check-not result, "F - test-gap-buffer-equal-fails" +} + +fn gap-buffers-equal? self: (addr gap-buffer), g: (addr gap-buffer) -> _/eax: boolean { + var tmp/eax: int <- gap-buffer-length self + var len/ecx: int <- copy tmp + var leng/eax: int <- gap-buffer-length g + compare len, leng + { + break-if-= + return 0/false + } + var i/edx: int <- copy 0 + { + compare i, len + break-if->= + { + var tmp/eax: grapheme <- gap-index self, i + var curr/ecx: grapheme <- copy tmp + var currg/eax: grapheme <- gap-index g, i + compare curr, currg + break-if-= + return 0/false + } + i <- increment + loop + } + return 1/true +} + +fn gap-index _self: (addr gap-buffer), _n: int -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + var n/ebx: int <- copy _n + # if n < left->length, index into left + var left/edi: (addr grapheme-stack) <- get self, left + var left-len-a/edx: (addr int) <- get left, top + compare n, *left-len-a + { + break-if->= + var data-ah/eax: (addr handle array grapheme) <- get left, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var result/eax: (addr grapheme) <- index data, n + return *result + } + # shrink n + n <- subtract *left-len-a + # if n < right->length, index into right + var right/edi: (addr grapheme-stack) <- get self, right + var right-len-a/edx: (addr int) <- get right, top + compare n, *right-len-a + { + break-if->= + var data-ah/eax: (addr handle array grapheme) <- get right, data + var data/eax: (addr array grapheme) <- lookup *data-ah + # idx = right->len - n - 1 + var idx/ebx: int <- copy n + idx <- subtract *right-len-a + idx <- negate + idx <- subtract 1 + var result/eax: (addr grapheme) <- index data, idx + return *result + } + # error + abort "gap-index: out of bounds" + return 0 +} + +fn test-gap-buffers-equal? { + var _a: gap-buffer + var a/esi: (addr gap-buffer) <- address _a + initialize-gap-buffer-with a, "abc" + var _b: gap-buffer + var b/edi: (addr gap-buffer) <- address _b + initialize-gap-buffer-with b, "abc" + var _c: gap-buffer + var c/ebx: (addr gap-buffer) <- address _c + initialize-gap-buffer-with c, "ab" + var _d: gap-buffer + var d/edx: (addr gap-buffer) <- address _d + initialize-gap-buffer-with d, "abd" + # + var result/eax: boolean <- gap-buffers-equal? a, a + check result, "F - test-gap-buffers-equal? - reflexive" + result <- gap-buffers-equal? a, b + check result, "F - test-gap-buffers-equal? - equal" + # length not equal + result <- gap-buffers-equal? a, c + check-not result, "F - test-gap-buffers-equal? - not equal" + # contents not equal + result <- gap-buffers-equal? a, d + check-not result, "F - test-gap-buffers-equal? - not equal 2" + result <- gap-buffers-equal? d, a + check-not result, "F - test-gap-buffers-equal? - not equal 3" +} + +fn test-gap-buffer-index { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "abc" + # gap is at end, all contents are in left + var g/eax: grapheme <- gap-index gap, 0 + var x/ecx: int <- copy g + check-ints-equal x, 0x61/a, "F - test-gap-index/left-1" + var g/eax: grapheme <- gap-index gap, 1 + var x/ecx: int <- copy g + check-ints-equal x, 0x62/b, "F - test-gap-index/left-2" + var g/eax: grapheme <- gap-index gap, 2 + var x/ecx: int <- copy g + check-ints-equal x, 0x63/c, "F - test-gap-index/left-3" + # now check when everything is to the right + gap-to-start gap + rewind-gap-buffer gap + var g/eax: grapheme <- gap-index gap, 0 + var x/ecx: int <- copy g + check-ints-equal x, 0x61/a, "F - test-gap-index/right-1" + var g/eax: grapheme <- gap-index gap, 1 + var x/ecx: int <- copy g + check-ints-equal x, 0x62/b, "F - test-gap-index/right-2" + var g/eax: grapheme <- gap-index gap, 2 + var x/ecx: int <- copy g + check-ints-equal x, 0x63/c, "F - test-gap-index/right-3" +} + +fn copy-gap-buffer _src-ah: (addr handle gap-buffer), _dest-ah: (addr handle gap-buffer) { + # obtain src-a, dest-a + var src-ah/eax: (addr handle gap-buffer) <- copy _src-ah + var _src-a/eax: (addr gap-buffer) <- lookup *src-ah + var src-a/esi: (addr gap-buffer) <- copy _src-a + var dest-ah/eax: (addr handle gap-buffer) <- copy _dest-ah + var _dest-a/eax: (addr gap-buffer) <- lookup *dest-ah + var dest-a/edi: (addr gap-buffer) <- copy _dest-a + # copy left grapheme-stack + var src/ecx: (addr grapheme-stack) <- get src-a, left + var dest/edx: (addr grapheme-stack) <- get dest-a, left + copy-grapheme-stack src, dest + # copy right grapheme-stack + src <- get src-a, right + dest <- get dest-a, right + copy-grapheme-stack src, dest +} + +fn gap-buffer-is-decimal-integer? _self: (addr gap-buffer) -> _/eax: boolean { + var self/esi: (addr gap-buffer) <- copy _self + var curr/ecx: (addr grapheme-stack) <- get self, left + var result/eax: boolean <- grapheme-stack-is-decimal-integer? curr + { + compare result, 0/false + break-if-= + curr <- get self, right + result <- grapheme-stack-is-decimal-integer? curr + } + return result +} + +fn test-render-gap-buffer-without-cursor { + # setup + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "abc" + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 0/no-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "abc ", "F - test-render-gap-buffer-without-cursor" + check-ints-equal x, 4, "F - test-render-gap-buffer-without-cursor: result" + # abc + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, " ", "F - test-render-gap-buffer-without-cursor: bg" +} + +fn test-render-gap-buffer-with-cursor-at-end { + # setup + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "abc" + gap-to-end gap + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "abc ", "F - test-render-gap-buffer-with-cursor-at-end" + # we've drawn one extra grapheme for the cursor + check-ints-equal x, 4, "F - test-render-gap-buffer-with-cursor-at-end: result" + # abc + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, " |", "F - test-render-gap-buffer-with-cursor-at-end: bg" +} + +fn test-render-gap-buffer-with-cursor-in-middle { + # setup + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "abc" + gap-to-end gap + var dummy/eax: grapheme <- gap-left gap + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "abc ", "F - test-render-gap-buffer-with-cursor-in-middle" + check-ints-equal x, 4, "F - test-render-gap-buffer-with-cursor-in-middle: result" + # abc + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, " | ", "F - test-render-gap-buffer-with-cursor-in-middle: bg" +} + +fn test-render-gap-buffer-with-cursor-at-start { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "abc" + gap-to-start gap + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "abc ", "F - test-render-gap-buffer-with-cursor-at-start" + check-ints-equal x, 4, "F - test-render-gap-buffer-with-cursor-at-start: result" + # abc + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, "| ", "F - test-render-gap-buffer-with-cursor-at-start: bg" +} + +fn test-render-gap-buffer-highlight-matching-close-paren { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "(a)" + gap-to-start gap + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "(a) ", "F - test-render-gap-buffer-highlight-matching-close-paren" + check-ints-equal x, 4, "F - test-render-gap-buffer-highlight-matching-close-paren: result" + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, "| ", "F - test-render-gap-buffer-highlight-matching-close-paren: cursor" + check-screen-row-in-color screen, 0xf/fg=highlight, 0/y, " ) ", "F - test-render-gap-buffer-highlight-matching-close-paren: matching paren" +} + +fn test-render-gap-buffer-highlight-matching-open-paren { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "(a)" + gap-to-end gap + var dummy/eax: grapheme <- gap-left gap + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "(a) ", "F - test-render-gap-buffer-highlight-matching-open-paren" + check-ints-equal x, 4, "F - test-render-gap-buffer-highlight-matching-open-paren: result" + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, " | ", "F - test-render-gap-buffer-highlight-matching-open-paren: cursor" + check-screen-row-in-color screen, 0xf/fg=highlight, 0/y, "( ", "F - test-render-gap-buffer-highlight-matching-open-paren: matching paren" +} + +fn test-render-gap-buffer-highlight-matching-open-paren-of-end { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "(a)" + gap-to-end gap + # setup: screen + var screen-on-stack: screen + var screen/edi: (addr screen) <- address screen-on-stack + initialize-screen screen, 5, 4, 0/no-pixel-graphics + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor, 3/fg, 0xc5/bg=blue-bg + check-screen-row screen, 0/y, "(a) ", "F - test-render-gap-buffer-highlight-matching-open-paren-of-end" + check-ints-equal x, 4, "F - test-render-gap-buffer-highlight-matching-open-paren-of-end: result" + check-background-color-in-screen-row screen, 3/bg=reverse, 0/y, " |", "F - test-render-gap-buffer-highlight-matching-open-paren-of-end: cursor" + check-screen-row-in-color screen, 0xf/fg=highlight, 0/y, "( ", "F - test-render-gap-buffer-highlight-matching-open-paren-of-end: matching paren" +} + +# should I highlight a matching open paren? And if so, at what depth from top of left? +# basically there are two cases to disambiguate here: +# Usually the cursor is at top of right. Highlight first '(' at depth 0 from top of left. +# If right is empty, match the ')' _before_ cursor. Highlight first '(' at depth _1_ from top of left. +fn highlight-matching-open-paren? _gap: (addr gap-buffer), render-cursor?: boolean -> _/ebx: boolean, _/edi: int { + # if not rendering cursor, return + compare render-cursor?, 0/false + { + break-if-!= + return 0/false, 0 + } + var gap/esi: (addr gap-buffer) <- copy _gap + var stack/edi: (addr grapheme-stack) <- get gap, right + var top-addr/eax: (addr int) <- get stack, top + var top-index/ecx: int <- copy *top-addr + compare top-index, 0 + { + break-if-> + # if cursor at end, return (char before cursor == ')', 1) + stack <- get gap, left + top-addr <- get stack, top + top-index <- copy *top-addr + compare top-index, 0 + { + break-if-> + return 0/false, 0 + } + top-index <- decrement + var data-ah/eax: (addr handle array grapheme) <- get stack, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var g/eax: (addr grapheme) <- index data, top-index + compare *g, 0x29/close-paren + { + break-if-= + return 0/false, 0 + } + return 1/true, 1 + } + # cursor is not at end; return (char at cursor == ')') + top-index <- decrement + var data-ah/eax: (addr handle array grapheme) <- get stack, data + var data/eax: (addr array grapheme) <- lookup *data-ah + var g/eax: (addr grapheme) <- index data, top-index + compare *g, 0x29/close-paren + { + break-if-= + return 0/false, 0 + } + return 1/true, 0 +} + +fn test-highlight-matching-open-paren { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "(a)" + gap-to-end gap + var highlight-matching-open-paren?/ebx: boolean <- copy 0/false + var open-paren-depth/edi: int <- copy 0 + highlight-matching-open-paren?, open-paren-depth <- highlight-matching-open-paren? gap, 0/no-cursor + check-not highlight-matching-open-paren?, "F - test-highlight-matching-open-paren: no cursor" + highlight-matching-open-paren?, open-paren-depth <- highlight-matching-open-paren? gap, 1/render-cursor + check highlight-matching-open-paren?, "F - test-highlight-matching-open-paren: at end immediately after ')'" + check-ints-equal open-paren-depth, 1, "F - test-highlight-matching-open-paren: depth at end immediately after ')'" + var dummy/eax: grapheme <- gap-left gap + highlight-matching-open-paren?, open-paren-depth <- highlight-matching-open-paren? gap, 1/render-cursor + check highlight-matching-open-paren?, "F - test-highlight-matching-open-paren: on ')'" + dummy <- gap-left gap + highlight-matching-open-paren?, open-paren-depth <- highlight-matching-open-paren? gap, 1/render-cursor + check-not highlight-matching-open-paren?, "F - test-highlight-matching-open-paren: not on ')'" +} + +## some primitives for scanning through a gap buffer +# don't modify the gap buffer while scanning +# this includes moving the cursor around + +# restart scan without affecting gap-buffer contents +fn rewind-gap-buffer _self: (addr gap-buffer) { + var self/esi: (addr gap-buffer) <- copy _self + var dest/eax: (addr int) <- get self, left-read-index + copy-to *dest, 0 + dest <- get self, right-read-index + copy-to *dest, 0 +} + +fn gap-buffer-scan-done? _self: (addr gap-buffer) -> _/eax: boolean { + var self/esi: (addr gap-buffer) <- copy _self + # more in left? + var left/eax: (addr grapheme-stack) <- get self, left + var left-size/eax: int <- grapheme-stack-length left + var left-read-index/ecx: (addr int) <- get self, left-read-index + compare *left-read-index, left-size + { + break-if->= + return 0/false + } + # more in right? + var right/eax: (addr grapheme-stack) <- get self, right + var right-size/eax: int <- grapheme-stack-length right + var right-read-index/ecx: (addr int) <- get self, right-read-index + compare *right-read-index, right-size + { + break-if->= + return 0/false + } + # + return 1/true +} + +fn peek-from-gap-buffer _self: (addr gap-buffer) -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + # more in left? + var left/ecx: (addr grapheme-stack) <- get self, left + var left-size/eax: int <- grapheme-stack-length left + var left-read-index-a/edx: (addr int) <- get self, left-read-index + compare *left-read-index-a, left-size + { + break-if->= + var left-data-ah/eax: (addr handle array grapheme) <- get left, data + var left-data/eax: (addr array grapheme) <- lookup *left-data-ah + var left-read-index/ecx: int <- copy *left-read-index-a + var result/eax: (addr grapheme) <- index left-data, left-read-index + return *result + } + # more in right? + var right/ecx: (addr grapheme-stack) <- get self, right + var _right-size/eax: int <- grapheme-stack-length right + var right-size/ebx: int <- copy _right-size + var right-read-index-a/edx: (addr int) <- get self, right-read-index + compare *right-read-index-a, right-size + { + break-if->= + # read the right from reverse + var right-data-ah/eax: (addr handle array grapheme) <- get right, data + var right-data/eax: (addr array grapheme) <- lookup *right-data-ah + var right-read-index/ebx: int <- copy right-size + right-read-index <- subtract *right-read-index-a + right-read-index <- subtract 1 + var result/eax: (addr grapheme) <- index right-data, right-read-index + return *result + } + # if we get here there's nothing left + return 0/nul +} + +fn read-from-gap-buffer _self: (addr gap-buffer) -> _/eax: grapheme { + var self/esi: (addr gap-buffer) <- copy _self + # more in left? + var left/ecx: (addr grapheme-stack) <- get self, left + var left-size/eax: int <- grapheme-stack-length left + var left-read-index-a/edx: (addr int) <- get self, left-read-index + compare *left-read-index-a, left-size + { + break-if->= + var left-data-ah/eax: (addr handle array grapheme) <- get left, data + var left-data/eax: (addr array grapheme) <- lookup *left-data-ah + var left-read-index/ecx: int <- copy *left-read-index-a + var result/eax: (addr grapheme) <- index left-data, left-read-index + increment *left-read-index-a + return *result + } + # more in right? + var right/ecx: (addr grapheme-stack) <- get self, right + var _right-size/eax: int <- grapheme-stack-length right + var right-size/ebx: int <- copy _right-size + var right-read-index-a/edx: (addr int) <- get self, right-read-index + compare *right-read-index-a, right-size + { + break-if->= + # read the right from reverse + var right-data-ah/eax: (addr handle array grapheme) <- get right, data + var right-data/eax: (addr array grapheme) <- lookup *right-data-ah + var right-read-index/ebx: int <- copy right-size + right-read-index <- subtract *right-read-index-a + right-read-index <- subtract 1 + var result/eax: (addr grapheme) <- index right-data, right-read-index + increment *right-read-index-a + return *result + } + # if we get here there's nothing left + return 0/nul +} + +fn put-back-from-gap-buffer _self: (addr gap-buffer) { + var self/esi: (addr gap-buffer) <- copy _self + # more in right? + var right/eax: (addr grapheme-stack) <- get self, right + var right-size/eax: int <- grapheme-stack-length right + var right-read-index-a/eax: (addr int) <- get self, right-read-index + compare *right-read-index-a, 0 + { + break-if-<= + decrement *right-read-index-a + return + } + # more in left? + var left/eax: (addr grapheme-stack) <- get self, left + var left-size/eax: int <- grapheme-stack-length left + var left-read-index-a/eax: (addr int) <- get self, left-read-index + decrement *left-read-index-a +} + +fn test-read-from-gap-buffer { + var gap-storage: gap-buffer + var gap/esi: (addr gap-buffer) <- address gap-storage + initialize-gap-buffer-with gap, "abc" + # gap is at end, all contents are in left + var done?/eax: boolean <- gap-buffer-scan-done? gap + check-not done?, "F - test-read-from-gap-buffer/left-1/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0x61/a, "F - test-read-from-gap-buffer/left-1" + var done?/eax: boolean <- gap-buffer-scan-done? gap + check-not done?, "F - test-read-from-gap-buffer/left-2/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0x62/b, "F - test-read-from-gap-buffer/left-2" + var done?/eax: boolean <- gap-buffer-scan-done? gap + check-not done?, "F - test-read-from-gap-buffer/left-3/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0x63/c, "F - test-read-from-gap-buffer/left-3" + var done?/eax: boolean <- gap-buffer-scan-done? gap + check done?, "F - test-read-from-gap-buffer/left-4/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0/nul, "F - test-read-from-gap-buffer/left-4" + # now check when everything is to the right + gap-to-start gap + rewind-gap-buffer gap + var done?/eax: boolean <- gap-buffer-scan-done? gap + check-not done?, "F - test-read-from-gap-buffer/right-1/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0x61/a, "F - test-read-from-gap-buffer/right-1" + var done?/eax: boolean <- gap-buffer-scan-done? gap + check-not done?, "F - test-read-from-gap-buffer/right-2/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0x62/b, "F - test-read-from-gap-buffer/right-2" + var done?/eax: boolean <- gap-buffer-scan-done? gap + check-not done?, "F - test-read-from-gap-buffer/right-3/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0x63/c, "F - test-read-from-gap-buffer/right-3" + var done?/eax: boolean <- gap-buffer-scan-done? gap + check done?, "F - test-read-from-gap-buffer/right-4/done" + var g/eax: grapheme <- read-from-gap-buffer gap + var x/ecx: int <- copy g + check-ints-equal x, 0/nul, "F - test-read-from-gap-buffer/right-4" +} + +fn skip-spaces-from-gap-buffer self: (addr gap-buffer) { + var done?/eax: boolean <- gap-buffer-scan-done? self + compare done?, 0/false + break-if-!= + var g/eax: grapheme <- peek-from-gap-buffer self + { + compare g, 0x20/space + break-if-= + return + } + g <- read-from-gap-buffer self + loop +} + +fn edit-gap-buffer self: (addr gap-buffer), key: grapheme { + var g/edx: grapheme <- copy key + { + compare g, 8/backspace + break-if-!= + delete-before-gap self + return + } + { + compare g, 0x80/left-arrow + break-if-!= + var dummy/eax: grapheme <- gap-left self + return + } + { + compare g, 0x83/right-arrow + break-if-!= + var dummy/eax: grapheme <- gap-right self + return + } + { + compare g, 6/ctrl-f + break-if-!= + gap-to-start-of-next-word self + return + } + { + compare g, 2/ctrl-b + break-if-!= + gap-to-end-of-previous-word self + return + } + { + compare g, 1/ctrl-a + break-if-!= + gap-to-previous-start-of-line self + return + } + { + compare g, 5/ctrl-e + break-if-!= + gap-to-next-end-of-line self + return + } + { + compare g, 0x81/down-arrow + break-if-!= + gap-down self + return + } + { + compare g, 0x82/up-arrow + break-if-!= + gap-up self + return + } + { + compare g, 0x15/ctrl-u + break-if-!= + clear-gap-buffer self + return + } + { + compare g, 9/tab + break-if-!= + # tab = 2 spaces + add-code-point-at-gap self, 0x20/space + add-code-point-at-gap self, 0x20/space + return + } + # default: insert character + add-grapheme-at-gap self, g +} + +fn gap-to-start-of-next-word self: (addr gap-buffer) { + var curr/eax: grapheme <- copy 0 + # skip to next space + { + curr <- gap-right self + compare curr, -1 + break-if-= + compare curr, 0x20/space + break-if-= + compare curr, 0xa/newline + break-if-= + loop + } + # skip past spaces + { + curr <- gap-right self + compare curr, -1 + break-if-= + compare curr, 0x20/space + loop-if-= + compare curr, 0xa/space + loop-if-= + curr <- gap-left self + break + } +} + +fn gap-to-end-of-previous-word self: (addr gap-buffer) { + var curr/eax: grapheme <- copy 0 + # skip to previous space + { + curr <- gap-left self + compare curr, -1 + break-if-= + compare curr, 0x20/space + break-if-= + compare curr, 0xa/newline + break-if-= + loop + } + # skip past all spaces but one + { + curr <- gap-left self + compare curr, -1 + break-if-= + compare curr, 0x20/space + loop-if-= + compare curr, 0xa/space + loop-if-= + curr <- gap-right self + break + } +} + +fn gap-to-previous-start-of-line self: (addr gap-buffer) { + # skip past immediate newline + var dummy/eax: grapheme <- gap-left self + # skip to previous newline + { + dummy <- gap-left self + { + compare dummy, -1 + break-if-!= + return + } + { + compare dummy, 0xa/newline + break-if-!= + dummy <- gap-right self + return + } + loop + } +} + +fn gap-to-next-end-of-line self: (addr gap-buffer) { + # skip past immediate newline + var dummy/eax: grapheme <- gap-right self + # skip to next newline + { + dummy <- gap-right self + { + compare dummy, -1 + break-if-!= + return + } + { + compare dummy, 0xa/newline + break-if-!= + dummy <- gap-left self + return + } + loop + } +} + +fn gap-up self: (addr gap-buffer) { + # compute column + var col/edx: int <- count-columns-to-start-of-line self + # + gap-to-previous-start-of-line self + # skip ahead by up to col on previous line + var i/ecx: int <- copy 0 + { + compare i, col + break-if->= + var curr/eax: grapheme <- gap-right self + { + compare curr, -1 + break-if-!= + return + } + compare curr, 0xa/newline + { + break-if-!= + curr <- gap-left self + return + } + i <- increment + loop + } +} + +fn gap-down self: (addr gap-buffer) { + # compute column + var col/edx: int <- count-columns-to-start-of-line self + # skip to start of next line + gap-to-end-of-line self + var dummy/eax: grapheme <- gap-right self + # skip ahead by up to col on previous line + var i/ecx: int <- copy 0 + { + compare i, col + break-if->= + var curr/eax: grapheme <- gap-right self + { + compare curr, -1 + break-if-!= + return + } + compare curr, 0xa/newline + { + break-if-!= + curr <- gap-left self + return + } + i <- increment + loop + } +} + +fn count-columns-to-start-of-line self: (addr gap-buffer) -> _/edx: int { + var count/edx: int <- copy 0 + var dummy/eax: grapheme <- copy 0 + # skip to previous newline + { + dummy <- gap-left self + { + compare dummy, -1 + break-if-!= + return count + } + { + compare dummy, 0xa/newline + break-if-!= + dummy <- gap-right self + return count + } + count <- increment + loop + } + return count +} + +fn gap-to-end-of-line self: (addr gap-buffer) { + var dummy/eax: grapheme <- copy 0 + # skip to next newline + { + dummy <- gap-right self + { + compare dummy, -1 + break-if-!= + return + } + { + compare dummy, 0xa/newline + break-if-!= + dummy <- gap-left self + return + } + loop + } +} |