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Diffstat (limited to 'shell/gap-buffer.mu')
| -rw-r--r-- | shell/gap-buffer.mu | 781 |
1 files changed, 781 insertions, 0 deletions
diff --git a/shell/gap-buffer.mu b/shell/gap-buffer.mu new file mode 100644 index 00000000..81537e9c --- /dev/null +++ b/shell/gap-buffer.mu @@ -0,0 +1,781 @@ +# primitive for editing a single word + +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), max-word-size: int { + var self/esi: (addr gap-buffer) <- copy _self + var left/eax: (addr grapheme-stack) <- get self, left + initialize-grapheme-stack left, max-word-size + var right/eax: (addr grapheme-stack) <- get self, right + initialize-grapheme-stack right, max-word-size +} + +# just for tests +fn initialize-gap-buffer-with self: (addr gap-buffer), s: (addr array byte) { + initialize-gap-buffer self, 0x10/max-word-size + var stream-storage: (stream byte 0x10/max-word-size) + var stream/ecx: (addr stream byte) <- address stream-storage + write stream, s + { + var done?/eax: boolean <- stream-empty? stream + compare done?, 0/false + break-if-!= + var g/eax: grapheme <- read-grapheme stream + add-grapheme-at-gap self, g + loop + } +} + +fn emit-gap-buffer _self: (addr gap-buffer), out: (addr stream byte) { + var self/esi: (addr gap-buffer) <- copy _self + clear-stream out + 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 + } +} + +# 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 -> _/eax: int, _/ecx: int { + var gap/esi: (addr gap-buffer) <- copy _gap + var left/edx: (addr grapheme-stack) <- get gap, left + 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 + 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? + # decide whether we still need to print a cursor + var bg/ebx: int <- copy 0 + 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-= + bg <- copy 7/cursor + } + # 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, 3/fg=cyan, bg + return x2, y2 +} + +fn render-gap-buffer screen: (addr screen), gap: (addr gap-buffer), x: int, y: int, render-cursor?: boolean -> _/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? + 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 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/max-word-size) + 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 + # + var c/eax: grapheme <- copy 0x61/a + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + # 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 + # + var c/eax: grapheme <- copy 0x61/a + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + 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 + # + var c/eax: grapheme <- copy 0x61/a + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + 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 + var c/eax: grapheme <- copy 0x61/a + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + add-grapheme-at-gap g, c + # + 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 + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 0/no-cursor + 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, 7/bg=cursor, 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 + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor + 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, 7/bg=cursor, 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 + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor + 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, 7/bg=cursor, 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 + # + var x/eax: int <- render-gap-buffer screen, gap, 0/x, 0/y, 1/show-cursor + 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, 7/bg=cursor, 0/y, "| ", "F - test-render-gap-buffer-with-cursor-at-start: bg" +} + +## 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 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-whitespace-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-= + compare g, 0xa/newline + 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 + } + # arrow keys + { + compare g, 4/ctrl-d + break-if-!= + # ctrl-d: cursor down + return + } + { + compare g, 0x15/ctrl-u + break-if-!= + # ctrl-u: cursor up + return + } + # default: insert character + add-grapheme-at-gap self, g +} + +fn cursor-on-final-line? self: (addr gap-buffer) -> _/eax: boolean { + return 1/true +} |