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# Incomplete first attempt at parsing headings.
#
# The state machine is getting out of control, and I notice old bugs like
# turning '*abc_' into bold text.
fn main args: (addr array (addr array byte)) -> exit-status/ebx: int {
var filename/eax: (addr array byte) <- first-arg args
var file/esi: (addr buffered-file) <- load-file filename
enable-screen-grid-mode
var nrows/eax: int <- copy 0
var ncols/ecx: int <- copy 0
nrows, ncols <- screen-size
enable-keyboard-immediate-mode
{
render file, nrows, ncols
var key/eax: byte <- read-key
compare key, 0x71 # 'q'
loop-if-!=
}
enable-keyboard-type-mode
enable-screen-type-mode
exit-status <- copy 0
}
type render-state {
current-state: int # enum 0: normal, 1: bold, 2: heading
start-of-line?: boolean
num-hashes-seen?: int
}
# decide how to lay out pages on screen
fn render in: (addr buffered-file), nrows: int, ncols: int {
# Fit multiple pages on screen on separate columns, each wide enough to read
# comfortably.
# Pages are separated horizontally by a 'page margin'. Among other reasons,
# this allows the odd line to bleed out on the right if necessary.
#
# hardcoded parameters:
# top-margin
# page-margin
# page-width
var _r: render-state
var r/edi: (addr render-state) <- address _r
# r->start-of-line? = true
var s/eax: (addr boolean) <- get r, start-of-line?
copy-to *s, 1 # true
var toprow/eax: int <- copy 2 # top-margin
var botrow/ecx: int <- copy nrows
var leftcol/edx: int <- copy 5 # page-margin
var rightcol/ebx: int <- copy leftcol
rightcol <- add 0x40 # page-width = 64 characters
start-color 0xec, 7 # 236 = darkish gray
{
compare rightcol, ncols
break-if->=
render-page in, toprow, leftcol, botrow, rightcol, r
leftcol <- copy rightcol
leftcol <- add 5 # page-margin
rightcol <- copy leftcol
rightcol <- add 0x40 # page-width
loop
}
}
fn render-page in: (addr buffered-file), toprow: int, leftcol: int, botrow: int, rightcol: int, _r: (addr render-state) {
var r/edi: (addr render-state) <- copy _r
var state/esi: (addr int) <- get r, current-state
clear toprow, leftcol, botrow, rightcol
var row/ecx: int <- copy toprow
$line-loop: {
compare row, botrow
break-if->=
var col/edx: int <- copy leftcol
move-cursor row, col
$char-loop: {
compare col, rightcol
break-if->=
var c/eax: byte <- read-byte-buffered in
compare c, 0xffffffff # EOF marker
break-if-= $line-loop
$change-state: {
compare *state, 0 # normal
{
break-if-!=
compare c, 0x2a # '*'
{
break-if-!=
# r->current-state == 0 && c == '*' => bold text
start-bold
copy-to *state, 1
break $change-state
}
compare c, 0x5f # '_'
{
break-if-!=
# r->current-state == 0 && c == '_' => bold text
start-bold
copy-to *state, 1
break $change-state
}
compare c, 0x23 # '#'
{
break-if-!=
var s/eax: (addr boolean) <- get r, start-of-line?
compare *s, 1
{
break-if-!=
# r->current-state == 0 && c == '#' && at start of line => count '#'s
var h/eax: (addr int) <- get r, num-hashes-seen?
increment *h
break $change-state
}
break $change-state
}
break $change-state
}
compare *state, 1 # bold
{
break-if-!=
compare c, 0x2a # '*'
{
break-if-!=
# r->current-state == 1 && c == '*' => print c, then normal text
print-byte-to-screen c
col <- increment
reset-formatting
start-color 0xec, 7 # 236 = darkish gray
copy-to *state, 0
loop $char-loop
}
compare c, 0x5f # '_'
{
break-if-!=
# r->current-state == 1 && c == '_' => print c, then normal text
print-byte-to-screen c
col <- increment
reset-formatting
start-color 0xec, 7 # 236 = darkish gray
copy-to *state, 0
loop $char-loop
}
break $change-state
}
} # $change-state
# update a few attributes of the state based on c without changing the state itself
compare c, 0xa # newline
{
break-if-!=
# c is newline
var s/eax: (addr boolean) <- get r, start-of-line?
copy-to *s, 1 # true
# switch to normal text
reset-formatting
start-color 0xec, 7 # 236 = darkish gray
# no need to print newlines
break $char-loop
}
compare c, 0x20 # space
{
break-if-=
# c is not newline or space
var s/eax: (addr boolean) <- get r, start-of-line?
copy-to *s, 0 # false
}
# print c
print-byte-to-screen c
col <- increment
loop
}
row <- increment
loop
}
}
fn clear toprow: int, leftcol: int, botrow: int, rightcol: int {
var row/ecx: int <- copy toprow
{
compare row, botrow
break-if->=
var col/edx: int <- copy leftcol
move-cursor row, col
{
compare col, rightcol
break-if->=
print-string-to-screen " "
col <- increment
loop
}
row <- increment
loop
}
}
fn first-arg args-on-stack: (addr array (addr array byte)) -> out/eax: (addr array byte) {
var args/eax: (addr array (addr array byte)) <- copy args-on-stack
var result/eax: (addr addr array byte) <- index args, 1
out <- copy *result
}
fn load-file filename: (addr array byte) -> out/esi: (addr buffered-file) {
var result: (handle buffered-file)
{
var tmp1/eax: (addr handle buffered-file) <- address result
open filename, 0, tmp1
}
var tmp2/eax: (addr buffered-file) <- lookup result
out <- copy tmp2
}
fn dump in: (addr buffered-file) {
var c/eax: byte <- read-byte-buffered in
compare c, 0xffffffff # EOF marker
break-if-=
print-byte-to-screen c
loop
}
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