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#[derive(Debug, Clone)]
pub enum Block {
Header(usize, Vec<Span>),
Paragraph(Vec<Span>),
Blockquote(Vec<Block>),
CodeBlock(Option<String>, String),
LatexBlock(String),
OrderedList(Vec<Vec<Block>>),
UnorderedList(Vec<Vec<Block>>),
Raw(String),
Hr,
}
#[derive(Debug, Clone)]
pub enum Span {
Break,
Text(String),
Code(String),
Link(String, String),
Image(String, String),
Emphasis(Vec<Span>),
Strong(Vec<Span>),
Latex(String),
}
pub fn parse(mut s: &str) -> Vec<Block> {
let mut blocks = Vec::new();
while s.len() != 0 {
if s.starts_with("\n") {
s = &s[1..];
continue;
}
// TODO bad code here
if let Some((block, rest)) = try_header(s) {
s = rest;
blocks.push(block);
continue;
}
if let Some((block, rest)) = try_latex_block(s) {
s = rest;
blocks.push(block);
continue;
}
if let Some((block, rest)) = try_code_block(s) {
s = rest;
blocks.push(block);
continue;
}
if let Some((block, rest)) = try_list(s) {
s = rest;
blocks.push(block);
continue;
}
let lf = [s.find("\n\n"), s.find("\n-")]
.iter()
.filter_map(|e| *e)
.min()
.unwrap_or(s.len());
let span = Span::parse(&s[..lf]);
blocks.push(Block::Paragraph(span));
if lf >= s.len() {
break;
}
s = &s[lf + 1..];
}
blocks
}
fn try_code_block(mut s: &str) -> Option<(Block, &str)> {
if !s.starts_with("```") {
return None;
}
s = &s[3..];
let lf = s.find('\n')?;
let syntax = if lf != 0 {
Some(String::from(&s[0..lf]))
} else {
None
};
s = &s[lf..];
let end = s.find("\n```\n")?;
Some((
Block::CodeBlock(syntax, String::from(&s[..end])),
&s[end + 4..],
))
}
fn try_latex_block(mut s: &str) -> Option<(Block, &str)> {
if !s.starts_with("$$") {
return None;
}
s = &s[2..];
let end = s.find("$$")?;
Some((Block::LatexBlock(String::from(&s[..end])), &s[end + 2..]))
}
fn try_list(mut s: &str) -> Option<(Block, &str)> {
if !s.starts_with("-") {
return None;
};
let mut blocks = vec![];
loop {
if !s.starts_with("-") || s.len() == 0 {
break Some((Block::UnorderedList(blocks), s));
}
s = &s[1..];
let mut lf = s.find("\n").unwrap();
while s[lf + 1..].starts_with(" -") {
lf += 2 + s[lf + 2..].find("\n").unwrap();
}
eprintln!("{:?}", &s[..lf]);
let mut k = s[..lf]
.split("\n")
.map(|l| if l.starts_with(" ") { &l[2..] } else { &l })
.collect::<Vec<_>>()
.join("\n");
k.push('\n');
blocks.push(parse(&k));
s = &s[lf + 1..];
}
}
fn try_header(s: &str) -> Option<(Block, &str)> {
if s.starts_with("#") {
let mut u = 0;
while s.chars().nth(u)? == '#' {
u += 1;
}
let lf = s.find('\n')?;
Some((Block::Header(u, Span::parse(&s[u..lf])), &s[lf + 1..]))
} else {
None
}
}
impl Span {
pub fn parse(mut s: &str) -> Vec<Span> {
let mut spans = Vec::new();
while s.len() != 0 {
let nt = s.find(&['*', '_', '`', '[', '$']);
if let Some(nt) = nt {
spans.push(Span::Text(String::from(&s[..nt])));
s = &s[nt..];
if s.starts_with("**") {
s = &s[2..];
let end = s.find("**").expect("** not ended");
spans.push(Span::Strong(Span::parse(&s[..end])));
s = &s[end + 2..];
continue;
}
if s.starts_with("_") {
s = &s[1..];
let end = s.find("_").expect("_ not ended");
spans.push(Span::Emphasis(Span::parse(&s[..end])));
s = &s[end + 1..];
continue;
}
if s.starts_with("`") {
s = &s[1..];
let end = s.find("`").expect("` not ended");
spans.push(Span::Code(String::from(&s[..end])));
s = &s[end + 1..];
continue;
}
if s.starts_with("$") {
s = &s[1..];
let end = s.find("$").expect("$ not ended");
spans.push(Span::Latex(String::from(&s[..end])));
s = &s[end + 1..];
continue;
}
if s.starts_with("[") {
s = &s[1..];
let del = s.find("](").expect("]( expected");
let end = del + s[del..].find(")").expect(") expected");
spans.push(Span::Link(
String::from(&s[..del]),
String::from(&s[del + 2..end]),
));
s = &s[end + 1..];
continue;
}
panic!("{s:?}")
} else {
spans.push(Span::Text(String::from(s)));
break;
}
}
spans
}
}
|
