bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/mbe/src/expander/transcriber.rs')
-rw-r--r--crates/mbe/src/expander/transcriber.rs41
1 files changed, 39 insertions, 2 deletions
diff --git a/crates/mbe/src/expander/transcriber.rs b/crates/mbe/src/expander/transcriber.rs
index a4dbd907a3..d1bcf3dbcc 100644
--- a/crates/mbe/src/expander/transcriber.rs
+++ b/crates/mbe/src/expander/transcriber.rs
@@ -131,8 +131,9 @@ pub(super) fn transcribe<S: Span>(
template: &MetaTemplate<S>,
bindings: &Bindings<S>,
marker: impl Fn(&mut S) + Copy,
+ new_meta_vars: bool,
) -> ExpandResult<tt::Subtree<S>> {
- let mut ctx = ExpandCtx { bindings, nesting: Vec::new() };
+ let mut ctx = ExpandCtx { bindings, nesting: Vec::new(), new_meta_vars };
let mut arena: Vec<tt::TokenTree<S>> = Vec::new();
expand_subtree(&mut ctx, template, None, &mut arena, marker)
}
@@ -152,6 +153,7 @@ struct NestingState {
struct ExpandCtx<'a, S> {
bindings: &'a Bindings<S>,
nesting: Vec<NestingState>,
+ new_meta_vars: bool,
}
fn expand_subtree<S: Span>(
@@ -284,7 +286,13 @@ fn expand_subtree<S: Span>(
}
}
- let c = match count(ctx, binding, 0, *depth) {
+ let res = if ctx.new_meta_vars {
+ count(ctx, binding, 0, depth.unwrap_or(0))
+ } else {
+ count_old(ctx, binding, 0, *depth)
+ };
+
+ let c = match res {
Ok(c) => c,
Err(e) => {
// XXX: It *might* make sense to emit a dummy integer value like `0` here.
@@ -548,3 +556,32 @@ fn count<S>(
Binding::Fragment(_) | Binding::Missing(_) => Ok(1),
}
}
+
+fn count_old<S>(
+ ctx: &ExpandCtx<'_, S>,
+ binding: &Binding<S>,
+ our_depth: usize,
+ count_depth: Option<usize>,
+) -> Result<usize, CountError> {
+ match binding {
+ Binding::Nested(bs) => match count_depth {
+ None => bs.iter().map(|b| count_old(ctx, b, our_depth + 1, None)).sum(),
+ Some(0) => Ok(bs.len()),
+ Some(d) => bs.iter().map(|b| count_old(ctx, b, our_depth + 1, Some(d - 1))).sum(),
+ },
+ Binding::Empty => Ok(0),
+ Binding::Fragment(_) | Binding::Missing(_) => {
+ if our_depth == 0 {
+ // `${count(t)}` is placed inside the innermost repetition. This includes cases
+ // where `t` is not a repeated fragment.
+ Err(CountError::Misplaced)
+ } else if count_depth.is_none() {
+ Ok(1)
+ } else {
+ // We've reached at the innermost repeated fragment, but the user wants us to go
+ // further!
+ Err(CountError::OutOfBounds)
+ }
+ }
+ }
+}