tada/src/parser/basic.rs

57 lines
1.4 KiB
Rust

//! Corresponds to `ast::basic`.
use chumsky::prelude::*;
use chumsky::text::Character;
use crate::ast::{Ident, Line, Space};
use crate::span::Span;
pub type Error = Simple<char, Span>;
// TODO https://github.com/rust-lang/rust/issues/63063
fn inline() -> impl Parser<char, (), Error = Error> + Clone {
filter(|c: &char| c.is_whitespace() && *c != '\n')
.repeated()
.to(())
}
fn newline() -> impl Parser<char, (), Error = Error> + Clone {
just('\n').to(())
}
fn line() -> impl Parser<char, Line, Error = Error> + Clone {
let empty = newline().to(Line::Empty);
let comment = just('#')
.ignore_then(take_until(newline()))
.map(|(s, _)| s)
.collect::<String>()
.map(Line::Comment);
empty.or(comment)
}
pub fn space() -> BoxedParser<'static, char, Space, Error> {
inline()
.ignore_then(line())
.repeated()
.then_ignore(inline())
.map_with_span(|lines, span| Space { lines, span })
.boxed()
}
pub fn ident() -> BoxedParser<'static, char, Ident, Error> {
text::ident()
.try_map(|name, span| {
if matches!(
&name as &str,
"nil" | "true" | "false" | "local" | "function" | "not" | "and" | "or"
) {
Err(Simple::custom(span, "identifier uses reserved name"))
} else {
Ok(Ident { name, span })
}
})
.boxed()
}