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Un-macro either

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Jackson Wambolt 2024-04-15 21:09:39 -05:00
parent 2f776f366f
commit 02c98f7519
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4 changed files with 37 additions and 39 deletions
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38
crates/compiler/parse/src/parser.rs
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@ -2403,7 +2403,7 @@ macro_rules! debug {
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = either!(
/// let parser = either(
/// word("hello", Problem::NotFound),
/// word("bye", Problem::NotFound)
/// );
@ -2426,27 +2426,25 @@ macro_rules! debug {
/// # }
/// # foo(&arena);
/// ```
#[macro_export]
macro_rules! either {
($p1:expr, $p2:expr) => {
move |arena: &'a bumpalo::Bump, state: $crate::state::State<'a>, min_indent: u32| {
let original_state = state.clone();
match $p1.parse(arena, state, min_indent) {
Ok((progress, output, state)) => {
Ok((progress, $crate::parser::Either::First(output), state))
}
Err((NoProgress, _)) => {
match $p2.parse(arena, original_state.clone(), min_indent) {
Ok((progress, output, state)) => {
Ok((progress, $crate::parser::Either::Second(output), state))
}
Err((progress, fail)) => Err((progress, fail)),
}
}
Err((MadeProgress, fail)) => Err((MadeProgress, fail)),
pub fn either<'a, OutputLeft, OutputRight, E: 'a>(
p1: impl Parser<'a, OutputLeft, E>,
p2: impl Parser<'a, OutputRight, E>,
) -> impl Parser<'a, Either<OutputLeft, OutputRight>, E> {
move |arena: &'a bumpalo::Bump, state: crate::state::State<'a>, min_indent: u32| {
let original_state = state.clone();
match p1.parse(arena, state, min_indent) {
Ok((progress, output, state)) => {
Ok((progress, crate::parser::Either::First(output), state))
}
Err((NoProgress, _)) => match p2.parse(arena, original_state.clone(), min_indent) {
Ok((progress, output, state)) => {
Ok((progress, crate::parser::Either::Second(output), state))
}
Err((progress, fail)) => Err((progress, fail)),
},
Err((MadeProgress, fail)) => Err((MadeProgress, fail)),
}
};
}
}
/// Given three parsers, parse them all but ignore the output of the first and last one.