parser: make parseExpr return Expr instead of Node

src/parser.zig

@@ -129,6 +129,8 @@ pub const Parser = struct {
         return false;
     }
 
+    // TODO maybe move helper functions to ast_helper.zig?
+
     fn mkFnDecl(
         self: *Parser,
         name: Token,
@@ -411,17 +413,20 @@ pub const Parser = struct {
         errdefer consts.deinit();
 
         _ = try self.consumeSingle(.Const);
-
         _ = try self.consumeSingle(.LeftParen);
 
         while (self.peek().ttype != .RightParen) {
             const const_name = try self.consumeSingle(.Identifier);
             _ = try self.consumeSingle(.Equal);
 
+            // const declarations dont have type, a future type system must
+            // check the output type of the expression and assign it to the
+            // const later on.
+
             var expr = try self.parseExpr();
             try consts.append(ast.SingleConst{
                 .name = const_name,
-                .expr = expr.Expr,
+                .expr = expr,
             });
         }
 
@@ -522,7 +527,7 @@ pub const Parser = struct {
 
     fn parseIfStmt(self: *@This()) !*Stmt {
         _ = try self.consumeSingle(.If);
-        var condition = (try self.parseExpr()).Expr;
+        var condition = try self.parseExpr();
 
         const then_branch = try self.parseStmtBlock();
 
@@ -550,7 +555,7 @@ pub const Parser = struct {
         if (self.check(.LeftBrace)) {
             body = try self.parseStmtBlock();
         } else {
-            expr = (try self.parseExpr()).Expr;
+            expr = try self.parseExpr();
             body = try self.parseStmtBlock();
         }
 
@@ -559,7 +564,7 @@ pub const Parser = struct {
 
     fn parseReturn(self: *@This()) !*Stmt {
         const tok = try self.consumeSingle(.Return);
-        const expr = (try self.parseExpr()).Expr;
+        const expr = try self.parseExpr();
         return try Stmt.mkReturn(self.allocator, tok, expr);
     }
 
@@ -567,20 +572,19 @@ pub const Parser = struct {
         _ = try self.consumeSingle(.Println);
 
         _ = try self.consumeSingle(.LeftParen);
-        var expr = (try self.parseExpr()).Expr;
+        var expr = try self.parseExpr();
         _ = try self.consumeSingle(.RightParen);
 
         return try Stmt.mkPrintln(self.allocator, expr);
     }
 
     fn parseStmtExpr(self: *@This()) !*Stmt {
-        var expr = (try self.parseExpr()).Expr;
+        var expr = try self.parseExpr();
         return try self.mkStmtExpr(expr);
     }
 
-    fn parseExpr(self: *@This()) anyerror!*Node {
+    fn parseExpr(self: *@This()) anyerror!*Expr {
-        var expr: *Expr = try self.parseAssignment();
+        return try self.parseAssignment();
-        return self.mkExpr(expr);
     }
 
     fn parseAssignment(self: *@This()) anyerror!*Expr {
@@ -784,13 +788,13 @@ pub const Parser = struct {
         if (!self.check(.RightParen)) {
 
             // emulating do-while really badly
-            var arg = (try self.parseExpr()).Expr;
+            var arg = try self.parseExpr();
             try args.append(arg);
 
             while (self.check(.Comma)) {
                 _ = try self.consumeSingle(.Comma);
 
-                arg = (try self.parseExpr()).Expr;
+                arg = try self.parseExpr();
                 try args.append(arg);
             }
         }
@@ -817,7 +821,7 @@ pub const Parser = struct {
             // TODO check .Comma for the quick initialization {val,val,val}
 
             _ = try self.consumeSingle(.Colon);
-            const field_value = (try self.parseExpr()).Expr;
+            const field_value = try self.parseExpr();
 
             try inits.append(ast.StructInit{
                 .field = field_name,
@@ -845,7 +849,7 @@ pub const Parser = struct {
 
             .LeftParen => blk: {
                 _ = try self.nextToken();
-                var expr = (try self.parseExpr()).Expr;
+                var expr = try self.parseExpr();
                 _ = try self.consume(.RightParen, "Expected ')' after expression");
 
                 // for groupings, we don't want to skip tokens as we already