Dict literal now accepts expressions as keys. Key values are computed at evalutetion time and still must be integer or string

scan/ast.go

@@ -98,7 +98,7 @@ func (ast *Ast) insert(tree, node *Term) (root *Term, err error) {
 		root = node
 		tree.SetParent(node)
 	} else {
-		err = node.Errorf("two adjacent operators: %q and %q", tree, node)
+		err = node.Errorf("two adjacent operators: %q and %q", tree, node.Source())
 	}
 	return
 }