Pretty print letrec

Author: Kmeakin

fathom/src/surface.rs

@@ -542,8 +542,8 @@ mod tests {
     #[cfg(target_pointer_width = "64")]
     fn term_size() {
         assert_eq!(std::mem::size_of::<Term<()>>(), 32);
-        assert_eq!(std::mem::size_of::<Term<ByteRange>>(), 56);
-        assert_eq!(std::mem::size_of::<Term<FileRange>>(), 64);
+        assert_eq!(std::mem::size_of::<Term<ByteRange>>(), 40);
+        assert_eq!(std::mem::size_of::<Term<FileRange>>(), 48);
     }
 
     #[test]

fathom/src/surface/distillation.rs

@@ -446,11 +446,11 @@ impl<'interner, 'arena, 'env> Context<'interner, 'arena, 'env> {
         match core_term {
             core::Term::ItemVar(_span, var) => match self.get_item_name(*var) {
                 Some(name) => Term::Name((), name),
-                None => todo!("misbound variable"), // TODO: error?
+                None => todo!("unbound item variable: `{var:?}`"), // TODO: error?
             },
             core::Term::LocalVar(_span, var) => match self.get_local_name(*var) {
                 Some(name) => Term::Name((), name),
-                None => todo!("misbound variable"), // TODO: error?
+                None => todo!("unbound local variable: `{var:?}`"), // TODO: error?
             },
             core::Term::MetaVar(_span, var) => match self.get_hole_name(*var) {
                 Some(name) => Term::Hole((), name),

fathom/src/surface/pretty.rs

@@ -160,18 +160,20 @@ impl<'interner, 'arena> Context<'interner, 'arena> {
                 self.concat([
                     self.text("let"),
                     self.space(),
-                    self.ann_pattern(&def.pattern, def.r#type.as_ref()),
-                    self.space(),
-                    self.text("="),
-                    self.softline(),
-                    self.term(&def.expr),
+                    self.let_def(def),
                     self.text(";"),
                 ])
                 .group(),
                 self.line(),
                 self.term(body_expr),
             ]),
-            Term::Letrec(_, _, _) => todo!(),
+            Term::Letrec(_, defs, body_expr) => self.sequence(
+                false,
+                self.concat([self.text("letrec"), self.space()]),
+                defs.iter().map(|def| self.let_def(def)),
+                self.text(","),
+                self.concat([self.text(";"), self.line(), self.term(body_expr)]),
+            ),
             Term::If(_, cond_expr, then_expr, mut else_expr) => {
                 let mut branches = Vec::new();