From 90499d4390402ae174f6a2e029b46ade92545496 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Tue, 2 May 2023 17:04:53 +0200
Subject: [PATCH] Use boxed slices instead ovecs in decl macros

---
 crates/mbe/src/benchmark.rs | 2 +-
 crates/mbe/src/lib.rs       | 6 +++---
 crates/mbe/src/parser.rs    | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/crates/mbe/src/benchmark.rs b/crates/mbe/src/benchmark.rs
index 212e0a02dbc..d640eea19a2 100644
--- a/crates/mbe/src/benchmark.rs
+++ b/crates/mbe/src/benchmark.rs
@@ -79,7 +79,7 @@ fn invocation_fixtures(rules: &FxHashMap<String, DeclarativeMacro>) -> Vec<(Stri
     let mut res = Vec::new();
 
     for (name, it) in rules {
-        for rule in &it.rules {
+        for rule in it.rules.iter() {
             // Generate twice
             for _ in 0..2 {
                 // The input are generated by filling the `Op` randomly.
diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs
index d20641062c1..80352aa4adc 100644
--- a/crates/mbe/src/lib.rs
+++ b/crates/mbe/src/lib.rs
@@ -104,7 +104,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 /// and `$()*` have special meaning (see `Var` and `Repeat` data structures)
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct DeclarativeMacro {
-    rules: Vec<Rule>,
+    rules: Box<[Rule]>,
     /// Highest id of the token we have in TokenMap
     shift: Shift,
     // This is used for correctly determining the behavior of the pat fragment
@@ -217,7 +217,7 @@ pub fn parse_macro_rules(
             validate(lhs)?;
         }
 
-        Ok(DeclarativeMacro { rules, shift: Shift::new(tt), is_2021 })
+        Ok(DeclarativeMacro { rules: rules.into_boxed_slice(), shift: Shift::new(tt), is_2021 })
     }
 
     /// The new, unstable `macro m {}` flavor.
@@ -250,7 +250,7 @@ pub fn parse_macro2(tt: &tt::Subtree, is_2021: bool) -> Result<DeclarativeMacro,
             validate(lhs)?;
         }
 
-        Ok(DeclarativeMacro { rules, shift: Shift::new(tt), is_2021 })
+        Ok(DeclarativeMacro { rules: rules.into_boxed_slice(), shift: Shift::new(tt), is_2021 })
     }
 
     pub fn expand(&self, tt: &tt::Subtree) -> ExpandResult<tt::Subtree> {
diff --git a/crates/mbe/src/parser.rs b/crates/mbe/src/parser.rs
index fd3d64719ac..0fbf832b06d 100644
--- a/crates/mbe/src/parser.rs
+++ b/crates/mbe/src/parser.rs
@@ -20,7 +20,7 @@
 /// Stuff to the right is a [`MetaTemplate`] template which is used to produce
 /// output.
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct MetaTemplate(pub(crate) Vec<Op>);
+pub(crate) struct MetaTemplate(pub(crate) Box<[Op]>);
 
 impl MetaTemplate {
     pub(crate) fn parse_pattern(pattern: &tt::Subtree) -> Result<MetaTemplate, ParseError> {
@@ -44,7 +44,7 @@ fn parse(tt: &tt::Subtree, mode: Mode) -> Result<MetaTemplate, ParseError> {
             res.push(op);
         }
 
-        Ok(MetaTemplate(res))
+        Ok(MetaTemplate(res.into_boxed_slice()))
     }
 }