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# Incomplete second attempt at parsing headings.
#
# This 'OO' approach seems more scalable. We hoist out all the outer framework
# for deciding when to increment 'col', when to increment 'row' and when to
# start a new page in a whole new part of the screen. Now it gets encapsulated
# into a series of small helpers that can be called from multiple places.
# Objects as coroutines.
#
# In spite of these advances, I need to first wrestle with a parsing issue.
# This text has a heading:
#
# abc *def
# # ghi*
#
# Ugh, so I can't do this translation in a single pass. At the first asterisk
# there's just not enough information to know whether it starts a bold text or
# not.
#
# Then again, maybe I should just keep going and not try to be compatible with
# GitHub-Flavored Markdown. Require that new headings are also new paragraphs.
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
enable-keyboard-immediate-mode
var nrows/eax: int <- copy 0
var ncols/ecx: int <- copy 0
nrows, ncols <- screen-size
var screen-position-state-storage: screen-position-state
var screen-position-state: (addr screen-position-state)
init-screen-position-state screen-position-state, nrows, ncols
{
render file, screen-position-state
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 screen-position-state {
nrows: int # const
ncols: int # const
toprow: int
botrow: int
leftcol: int
rightcol: int
row: int
col: int
}
fn render in: (addr buffered-file), state: (addr screen-position-state) {
start-drawing state
render-normal in, state
}
fn render-normal in: (addr buffered-file), state: (addr screen-position-state) {
{
# if done-drawing?(state) break
var done?/eax: boolean <- done-drawing? state
compare done?, 0
break-if-!=
#
var c/eax: byte <- read-byte-buffered in
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == '*') start-bold-on-screen, render-until-asterisk(in, state), reset
# else if (c == '_') start-bold-on-screen, render-until-underscore(in, state), reset
# else if (c == '#') compute-color, start color, render-header-line(in, state), reset
# else add-char(state, c)
}
}
fn render-until-asterisk in: (addr buffered-file), state: (addr screen-position-state) {
{
# if done-drawing?(state) break
var done?/eax: boolean <- done-drawing? state
compare done?, 0
break-if-!=
#
var c/eax: byte <- read-byte-buffered in
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == '*') break
# else add-char(state, c)
}
}
fn render-until-underscore in: (addr buffered-file), state: (addr screen-position-state) {
{
# if done-drawing?(state) break
var done?/eax: boolean <- done-drawing? state
compare done?, 0
break-if-!=
#
var c/eax: byte <- read-byte-buffered in
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == '_') break
# else add-char(state, c)
}
}
fn render-header-line in: (addr buffered-file), state: (addr screen-position-state) {
{
# if done-drawing?(state) break
var done?/eax: boolean <- done-drawing? state
compare done?, 0
break-if-!=
#
var c/eax: byte <- read-byte-buffered in
# if (c == EOF) break
compare c, 0xffffffff # EOF marker
break-if-=
# if (c == '*') break
# else add-char(state, c)
}
}
fn init-screen-position-state self: (addr screen-position-state), nrows: int, ncols: int {
# hardcoded parameters:
# top-margin
# page-margin
# page-width
var dest/eax: (addr int) <- copy 0
# self->nrows = nrows
# self->ncols = ncols
# self->toprow = top-margin
# self->botrow = nrows
# self->leftcol = page-margin
# self->rightcol = self->leftcol + page-width
# start-drawing(self)
}
fn start-drawing self: (addr screen-position-state) {
# self->row = toprow
# self->col = leftcol
}
fn add-char self: (addr screen-position-state), c: byte {
# print c
# self->col++
# if (self->col > self->rightcol) next-line(self)
}
fn next-line self: (addr screen-position-state) {
# self->row++
# if (self->row > self->botrow) next-page(self)
}
fn next-page self: (addr screen-position-state) {
# self->leftcol = self->rightcol + 5
# self->rightcol = self->leftcol + page-width
}
fn done-drawing? self: (addr screen-position-state) -> result/eax: boolean {
# self->rightcol >= self->ncols
}
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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