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use crate::constants::{BACKSLASH, COMMA, LBRACE, PERIOD, STAR};
use crate::node_pool::NodeID;
use crate::parse::parse_object;
use crate::types::{Cursor, MarkupKind, MatchError, ParseOpts, Parseable, Parser, Result};
/// Handle superscript and subscript
#[derive(Clone, Debug)]
pub enum PlainOrRec<'a> {
Plain(&'a str),
Rec(Vec<NodeID>),
}
macro_rules! parse_nscript {
($name: ident) => {
#[derive(Clone, Debug)]
pub struct $name<'a>(pub PlainOrRec<'a>);
impl<'a> Parseable<'a> for $name<'a> {
fn parse(
parser: &mut Parser<'a>,
mut cursor: Cursor<'a>,
parent: Option<NodeID>,
mut parse_opts: ParseOpts,
) -> Result<NodeID> {
if cursor.peek_rev(1)?.is_ascii_whitespace() {
return Err(MatchError::InvalidLogic);
}
let start = cursor.index;
// skip ^ or _
cursor.next();
match cursor.try_curr()? {
LBRACE => {
cursor.next();
parse_opts.markup.insert(MarkupKind::SupSub);
let mut content_vec = Vec::new();
loop {
match parse_object(parser, cursor, parent, parse_opts) {
Ok(id) => {
cursor.index = parser.pool[id].end;
content_vec.push(id);
}
Err(MatchError::MarkupEnd(kind)) => {
if !kind.contains(MarkupKind::SupSub) {
return Err(MatchError::InvalidLogic);
}
let new_id = parser.pool.reserve_id();
for id in content_vec.iter_mut() {
parser.pool[*id].parent = Some(new_id)
}
return Ok(parser.alloc_with_id(
Self(PlainOrRec::Rec(content_vec)),
start,
cursor.index + 1,
parent,
new_id,
));
}
ret @ Err(_) => {
return ret;
}
}
}
}
STAR => {
return Ok(parser.alloc(
Superscript(PlainOrRec::Plain(cursor.clamp_forwards(cursor.index + 2))),
start,
cursor.index + 2,
parent,
));
}
chr if !chr.is_ascii_whitespace() => {
// SIGN
// Either a plus sign character (+), a minus sign character (-), or the empty string.
// CHARS
// Either the empty string, or a string consisting of any number of alphanumeric characters,
// commas, backslashes, and dots.
// FINAL
// An alphanumeric character.
// all this is saying is that it has to be: alphanumeric,comma,backslash,dots.
// i don't see why you wouldn't just allow anything.
let ret = cursor.fn_while(|chr: u8| {
!chr.is_ascii_whitespace()
&& (chr.is_ascii_alphanumeric()
|| chr == COMMA
|| chr == BACKSLASH
|| chr == PERIOD)
})?;
cursor.move_to(ret.end);
// we won't go back to the start of the file since
// we know we started on an alphanumeric
while !cursor.peek_rev(1)?.is_ascii_alphanumeric() {
cursor.prev();
}
if cursor.index <= ret.start {
return Err(MatchError::InvalidLogic);
}
return Ok(parser.alloc(
Self(PlainOrRec::Plain(cursor.clamp_backwards(ret.start))),
start,
cursor.index,
parent,
));
}
_ => return Err(MatchError::InvalidLogic)?,
}
}
}
};
}
parse_nscript!(Subscript);
parse_nscript!(Superscript);
#[cfg(test)]
mod tests {
use crate::parse_org;
#[test]
fn basic_sup() {
let input = r"a^{\smiley}";
let pool = parse_org(input);
pool.print_tree();
}
}