conlang: Single-expression functions

compiler/cl-ast/src/ast.rs

@@ -146,7 +146,7 @@ pub struct Function {
     pub name: Sym,
     pub sign: TyFn,
     pub bind: Vec<Param>,
-    pub body: Option<Block>,
+    pub body: Option<Expr>,
 }
 
 /// A single parameter for a [Function]

compiler/cl-ast/src/ast_visitor/fold.rs

@@ -107,7 +107,7 @@ pub trait Fold {
             name: self.fold_sym(name),
             sign: self.fold_ty_fn(sign),
             bind: bind.into_iter().map(|p| self.fold_param(p)).collect(),
-            body: body.map(|b| self.fold_block(b)),
+            body: body.map(|b| self.fold_expr(b)),
         }
     }
     fn fold_param(&mut self, p: Param) -> Param {

compiler/cl-ast/src/ast_visitor/visit.rs

@@ -85,7 +85,7 @@ pub trait Visit<'a>: Sized {
         self.visit_ty_fn(sign);
         bind.iter().for_each(|p| self.visit_param(p));
         if let Some(b) = body {
-            self.visit_block(b)
+            self.visit_expr(b)
         }
     }
     fn visit_param(&mut self, p: &'a Param) {

compiler/cl-interpret/src/function/collect_upvars.rs

@@ -71,7 +71,7 @@ impl<'a> Visit<'a> for CollectUpvars<'_> {
             self.bind_name(name);
         }
         if let Some(body) = body {
-            self.visit_block(body);
+            self.visit_expr(body);
         }
     }
 

compiler/cl-parser/src/parser.rs

@@ -459,12 +459,11 @@ impl Parse<'_> for Function {
             sign,
             bind,
             body: match p.peek_kind(P)? {
-                TokenKind::LCurly => Some(Block::parse(p)?),
                 TokenKind::Semi => {
                     p.consume_peeked();
                     None
                 }
-                t => Err(p.error(Unexpected(t), P))?,
+                _ => Some(Expr::parse(p)?),
             },
         })
     }

compiler/cl-typeck/src/stage/populate.rs

@@ -108,7 +108,7 @@ impl<'a> Visit<'a> for Populator<'_, 'a> {
         self.visit_ty_fn(sign);
         bind.iter().for_each(|p| self.visit_param(p));
         if let Some(b) = body {
-            self.visit_block(b)
+            self.visit_expr(b)
         }
     }