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fn main args: (addr array addr array byte) -> exit-status/ebx: int {
# initialize fs from args[1]
var filename/eax: (addr array byte) <- first-arg args
var file-storage: (handle buffered-file)
var file-storage-addr/esi: (addr handle buffered-file) <- address file-storage
open filename, 0, file-storage-addr
var _fs/eax: (addr buffered-file) <- lookup file-storage
var fs/esi: (addr buffered-file) <- copy _fs
#
enable-screen-grid-mode
enable-keyboard-immediate-mode
# initialize screen state
var paginated-screen-storage: paginated-screen
var paginated-screen/eax: (addr paginated-screen) <- address paginated-screen-storage
initialize-paginated-screen paginated-screen, 0x40
normal-text paginated-screen
#
{
render paginated-screen, fs
var key/eax: byte <- read-key
compare key, 0x71 # 'q'
loop-if-!=
}
enable-keyboard-type-mode
enable-screen-type-mode
exit-status <- copy 0
}
fn render screen: (addr paginated-screen), fs: (addr buffered-file) {
start-drawing screen
render-normal screen, fs
}
fn render-normal screen: (addr paginated-screen), fs: (addr buffered-file) {
var newline-seen?/esi: boolean <- copy 0 # false
var start-of-paragraph?/edi: boolean <- copy 1 # true
var previous-grapheme/ebx: grapheme <- copy 0
$render-normal:loop: {
# if done-drawing?(screen) break
var done?/eax: boolean <- done-drawing? screen
compare done?, 0 # false
break-if-!=
var c/eax: grapheme <- read-grapheme-buffered fs
$render-normal:loop-body: {
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-= $render-normal:loop
## if (c == newline) perform some fairly sophisticated parsing for soft newlines
compare c, 0xa # newline
{
break-if-!=
# if it's the first newline, buffer it
compare newline-seen?, 0
{
break-if-!=
newline-seen? <- copy 1 # true
break $render-normal:loop-body
}
# otherwise render two newlines
{
break-if-=
add-grapheme screen, 0xa # newline
add-grapheme screen, 0xa # newline
newline-seen? <- copy 0 # false
start-of-paragraph? <- copy 1 # true
break $render-normal:loop-body
}
}
# if start of paragraph and c == '#', switch to header
compare start-of-paragraph?, 0
{
break-if-=
compare c, 0x23 # '#'
{
break-if-!=
render-header-line screen, fs
newline-seen? <- copy 1 # true
break $render-normal:loop-body
}
}
# c is not a newline
start-of-paragraph? <- copy 0 # false
# if c is unprintable (particularly a '\r' CR), skip it
compare c, 0x20
loop-if-< $render-normal:loop
# If there's a newline buffered and c is a space, print the buffered
# newline (hard newline).
# If there's a newline buffered and c is not a newline or space, print a
# space (soft newline).
compare newline-seen?, 0 # false
$render-normal:flush-buffered-newline: {
break-if-=
newline-seen? <- copy 0 # false
{
compare c, 0x20
break-if-!=
add-grapheme screen, 0xa # newline
break $render-normal:flush-buffered-newline
}
add-grapheme screen, 0x20 # space
# fall through to print c
}
## end soft newline support
$render-normal:whitespace-separated-regions: {
# if previous-grapheme wasn't whitespace, skip this block
{
compare previous-grapheme, 0x20 # space
break-if-=
compare previous-grapheme, 0xa # newline
break-if-=
break $render-normal:whitespace-separated-regions
}
# if (c == '*') switch to bold
compare c, 0x2a # '*'
{
break-if-!=
start-color-on-paginated-screen screen, 0xec, 7 # 236 = darkish gray
start-bold-on-paginated-screen screen
render-until-asterisk screen, fs
normal-text screen
break $render-normal:loop-body
}
# if (c == '_') switch to bold
compare c, 0x5f # '_'
{
break-if-!=
start-color-on-paginated-screen screen, 0xec, 7 # 236 = darkish gray
start-bold-on-paginated-screen screen
render-until-underscore screen, fs
normal-text screen
break $render-normal:loop-body
}
}
#
add-grapheme screen, c
} # $render-normal:loop-body
previous-grapheme <- copy c
loop
} # $render-normal:loop
}
fn render-header-line screen: (addr paginated-screen), fs: (addr buffered-file) {
$render-header-line:body: {
# compute color based on number of '#'s
var header-level/esi: int <- copy 1 # caller already grabbed one
var c/eax: grapheme <- copy 0
{
# if done-drawing?(screen) return
{
var done?/eax: boolean <- done-drawing? screen
compare done?, 0 # false
break-if-!= $render-header-line:body
}
#
c <- read-grapheme-buffered fs
# if (c != '#') break
compare c, 0x23 # '#'
break-if-!=
#
header-level <- increment
#
loop
}
start-heading screen, header-level
{
# if done-drawing?(screen) break
{
var done?/eax: boolean <- done-drawing? screen
compare done?, 0 # false
break-if-!=
}
#
c <- read-grapheme-buffered fs
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == newline) break
compare c, 0xa # newline
break-if-=
#
add-grapheme screen, c
#
loop
}
normal-text screen
}
}
# colors for a light background, going from bright to dark (meeting up with bold-text)
fn start-heading screen: (addr paginated-screen), header-level: int {
$start-heading:body: {
start-bold-on-paginated-screen screen
compare header-level, 1
{
break-if-!=
start-color-on-paginated-screen screen, 0xa0, 7
break $start-heading:body
}
compare header-level, 2
{
break-if-!=
start-color-on-paginated-screen screen, 0x7c, 7
break $start-heading:body
}
compare header-level, 3
{
break-if-!=
start-color-on-paginated-screen screen, 0x58, 7
break $start-heading:body
}
compare header-level, 4
{
break-if-!=
start-color-on-paginated-screen screen, 0x34, 7
break $start-heading:body
}
start-color-on-paginated-screen screen, 0xe8, 7
}
}
fn render-until-asterisk screen: (addr paginated-screen), fs: (addr buffered-file) {
{
# if done-drawing?(screen) break
var done?/eax: boolean <- done-drawing? screen
compare done?, 0 # false
break-if-!=
#
var c/eax: grapheme <- read-grapheme-buffered fs
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == '*') break
compare c, 0x2a # '*'
break-if-=
#
add-grapheme screen, c
#
loop
}
}
fn render-until-underscore screen: (addr paginated-screen), fs: (addr buffered-file) {
{
# if done-drawing?(screen) break
var done?/eax: boolean <- done-drawing? screen
compare done?, 0 # false
break-if-!=
#
var c/eax: grapheme <- read-grapheme-buffered fs
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == '_') break
compare c, 0x5f # '_'
break-if-=
#
add-grapheme screen, c
#
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 normal-text screen: (addr paginated-screen) {
reset-formatting-on-paginated-screen screen
start-color-on-paginated-screen screen, 0xec, 7 # 236 = darkish gray
}
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