Store Pattern in surface::Term::Let behind a pointer

Author: Kmeakin

fathom/src/surface.rs

@@ -186,7 +186,7 @@ pub enum Term<'arena, Range> {
     /// Let expressions.
     Let(
         Range,
-        Pattern<'arena, Range>,
+        &'arena Pattern<'arena, Range>,
         Option<&'arena Term<'arena, Range>>,
         &'arena Term<'arena, Range>,
         &'arena Term<'arena, Range>,
@@ -524,8 +524,8 @@ mod tests {
     #[test]
     #[cfg(target_pointer_width = "64")]
     fn term_size() {
-        assert_eq!(std::mem::size_of::<Term<()>>(), 48);
-        assert_eq!(std::mem::size_of::<Term<ByteRange>>(), 72);
+        assert_eq!(std::mem::size_of::<Term<()>>(), 40);
+        assert_eq!(std::mem::size_of::<Term<ByteRange>>(), 48);
     }
 
     #[test]

fathom/src/surface/distillation.rs

@@ -255,7 +255,7 @@ impl<'interner, 'arena, 'env> Context<'interner, 'arena, 'env> {
 
                 Term::Let(
                     (),
-                    Pattern::Name((), def_name),
+                    self.scope.to_scope(Pattern::Name((), def_name)),
                     Some(self.scope.to_scope(def_type)),
                     self.scope.to_scope(def_expr),
                     self.scope.to_scope(body_expr),
@@ -476,7 +476,7 @@ impl<'interner, 'arena, 'env> Context<'interner, 'arena, 'env> {
 
                 Term::Let(
                     (),
-                    Pattern::Name((), def_name),
+                    self.scope.to_scope(Pattern::Name((), def_name)),
                     Some(self.scope.to_scope(def_type)),
                     self.scope.to_scope(def_expr),
                     self.scope.to_scope(body_expr),

fathom/src/surface/grammar.lalrpop

@@ -121,7 +121,7 @@ LetTerm: Term<'arena, ByteRange> = {
     <start: @L> "let" <def_pattern: Pattern> <def_type: (":" <LetTerm>)?> "=" <def_expr: Term> ";" <body_expr: LetTerm> <end: @R> => {
         Term::Let(
             ByteRange::new(file_id, start, end),
-            def_pattern,
+            scope.to_scope(def_pattern),
             def_type.map(|def_type| scope.to_scope(def_type) as &_),
             scope.to_scope(def_expr),
             scope.to_scope(body_expr),