type gap-buffer {
left: grapheme-stack
right: grapheme-stack
}
fn initialize-gap-buffer _self: (addr gap-buffer) {
var self/esi: (addr gap-buffer) <- copy _self
var left/eax: (addr grapheme-stack) <- get self, left
initialize-grapheme-stack left, 0x10
var right/eax: (addr grapheme-stack) <- get self, right
initialize-grapheme-stack right, 0x10
}
fn render-gap-buffer screen: (addr screen), _gap: (addr gap-buffer) {
var gap/esi: (addr gap-buffer) <- copy _gap
var left/eax: (addr grapheme-stack) <- get gap, left
render-stack-from-bottom left, screen
var right/eax: (addr grapheme-stack) <- get gap, right
render-stack-from-top right, screen
}
fn gap-buffer-length _gap: (addr gap-buffer) -> result/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
result <- copy *tmp
result <- add left-length
}
# dump stack to screen from bottom to top
# don't move the cursor or anything
fn render-stack-from-bottom _self: (addr grapheme-stack), screen: (addr screen) {
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
print-grapheme screen, *g
i <- increment
loop
}
}
# dump stack to screen from top to bottom
# don't move the cursor or anything
fn render-stack-from-top _self: (addr grapheme-stack), screen: (addr screen) {
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
print-grapheme screen, *g
i <- decrement
loop
}
}
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-right _self: (addr gap-buffer) -> result/eax: grapheme {
$gap-right:body: {
var self/esi: (addr gap-buffer) <- copy _self
var g/edx: grapheme <- copy 0
{
var right/ecx: (addr grapheme-stack) <- get self, right
result <- pop-grapheme-stack right
compare result, -1
break-if-= $gap-right:body
g <- copy result
}
{
var left/ecx: (addr grapheme-stack) <- get self, left
# HERE: can't use 'result' here: "unknown variable 'result'"
push-grapheme-stack left, g
}
}
}
fn gap-left _self: (addr gap-buffer) -> result/eax: grapheme {
$gap-left:body: {
var self/esi: (addr gap-buffer) <- copy _self
var g/edx: grapheme <- copy 0
{
var left/ecx: (addr grapheme-stack) <- get self, left
result <- pop-grapheme-stack left
compare result, -1
break-if-= $gap-left:body
g <- copy result
}
{
var right/ecx: (addr grapheme-stack) <- get self, right
push-grapheme-stack right, g
}
}
}
type grapheme-stack {
data: (handle array grapheme)
top: int
}
fn initialize-grapheme-stack _self: (addr grapheme-stack), n: int {
var self/esi: (addr grapheme-stack) <- copy _self
var d/edi: (addr handle array grapheme) <- get self, data
populate d, n
var top/eax: (addr int) <- get self, top
copy-to *top, 0
}
fn push-grapheme-stack _self: (addr grapheme-stack), _val: grapheme {
var self/esi: (addr grapheme-stack) <- copy _self
var top-addr/ecx: (addr int) <- get self, top
var data-ah/edx: (addr handle array grapheme) <- get self, data
var data/eax: (addr array grapheme) <- lookup *data-ah
var top/edx: int <- copy *top-addr
var dest-addr/edx: (addr grapheme) <- index data, top
var val/eax: grapheme <- copy _val
copy-to *dest-addr, val
add-to *top-addr, 1
}
fn pop-grapheme-stack _self: (addr grapheme-stack) -> val/eax: grapheme {
$pop-grapheme-stack:body: {
var self/esi: (addr grapheme-stack) <- copy _self
var top-addr/ecx: (addr int) <- get self, top
{
compare *top-addr, 0
break-if->
val <- copy -1
break $pop-grapheme-stack:body
}
subtract-from *top-addr, 1
var data-ah/edx: (addr handle array grapheme) <- get self, data
var data/eax: (addr array grapheme) <- lookup *data-ah
var top/edx: int <- copy *top-addr
var result-addr/eax: (addr grapheme) <- index data, top
val <- copy *result-addr
}
}