Parse braced expressions and bracketed calls in headers 🗳

- Refactors the tokenizer to be lazy: It does not emit pre-parsed function tokens, but instead allows it's mode to be changed. The modes are tracked on a stack to allow nested compute/typesetting (pop/push).
- Introduces delimited groups into the parser, which make it easy to parse delimited expressions without handling the delimiters in the parsing code for the group's content. A group is started with `start_group`. When reaching the group's end (matching delimiter) the eat and peek methods will simply return `None` instead of the delimiter, stopping the content parser and bubbling up the call stack until `end_group` is called to clear up the situation.

1 files changed, 2 insertions, 3 deletions

diff --git a/benches/bench_parsing.rs b/benches/bench_parsing.rs
index a3a17a84..4a8a7eb2 100644
--- a/benches/bench_parsing.rs
+++ b/benches/bench_parsing.rs
@@ -1,18 +1,17 @@
 use criterion::{criterion_group, criterion_main, Criterion};
 use typstc::syntax::parsing::parse;
-use typstc::syntax::span::Pos;
 
 // 28 not too dense lines.
 const COMA: &str = include_str!("../tests/coma.typ");
 
 fn parsing_benchmark(c: &mut Criterion) {
     c.bench_function("parse-coma-28-lines", |b| {
-        b.iter(|| parse(COMA, Pos::ZERO))
+        b.iter(|| parse(COMA))
     });
 
     let long = COMA.repeat(100);
     c.bench_function("parse-coma-2800-lines", |b| {
-        b.iter(|| parse(&long, Pos::ZERO))
+        b.iter(|| parse(&long))
     });
 }