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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 0
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
}
# decide how to lay out pages on screen
fn render in: (addr buffered-file), nrows: int, ncols: int {
# Fit n 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 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
{
compare rightcol, ncols
break-if->=
render-page in, toprow, leftcol, botrow, rightcol
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 {
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 0, row, col
{
compare col, rightcol
break-if->=
var c/eax: byte <- read-byte-buffered in
compare c, 0xffffffff # EOF marker
break-if-= $line-loop
compare c, 0xa # newline
break-if-= # no need to print newlines
# print c
var g/eax: grapheme <- copy c
print-grapheme 0, g
col <- increment
loop
} # $char-loop
row <- increment
loop
} # $line-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 0, row, col
{
compare col, rightcol
break-if->=
print-string 0, " "
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-=
var g/eax: grapheme <- copy c
print-grapheme 0, g
loop
}
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