Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/mbe/src/lib.rs')
| -rw-r--r-- | crates/mbe/src/lib.rs | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs index 5445f8790f..d5de56312a 100644 --- a/crates/mbe/src/lib.rs +++ b/crates/mbe/src/lib.rs @@ -122,6 +122,9 @@ impl fmt::Display for CountError { } } +/// Index of the matched macro arm on successful expansion. +pub type MatchedArmIndex = Option<u32>; + /// This struct contains AST for a single `macro_rules` definition. What might /// be very confusing is that AST has almost exactly the same shape as /// `tt::TokenTree`, but there's a crucial difference: in macro rules, `$ident` @@ -251,7 +254,7 @@ impl DeclarativeMacro { new_meta_vars: bool, call_site: Span, def_site_edition: Edition, - ) -> ExpandResult<tt::Subtree<Span>> { + ) -> ExpandResult<(tt::Subtree<Span>, MatchedArmIndex)> { expander::expand_rules(&self.rules, tt, marker, new_meta_vars, call_site, def_site_edition) } } @@ -330,6 +333,10 @@ impl<T, E> ValueResult<T, E> { Self { value: Default::default(), err: Some(err) } } + pub fn zip_val<U>(self, other: U) -> ValueResult<(T, U), E> { + ValueResult { value: (self.value, other), err: self.err } + } + pub fn map<U>(self, f: impl FnOnce(T) -> U) -> ValueResult<U, E> { ValueResult { value: f(self.value), err: self.err } } |