Add RawExprAST
diff --git a/eval.go b/eval.go
index 2d1de66..333e6be 100644
--- a/eval.go
+++ b/eval.go
@@ -154,6 +154,13 @@
 	ev.curRule = nil
 }
 
+func (ev *Evaluator) evalRawExpr(ast *RawExprAST) {
+	result := ev.evalExpr(ast.expr)
+	if result != "" {
+		fmt.Printf("%s:%d: *** missing separator.  Stop.\n", ast.filename, ast.lineno)
+	}
+}
+
 func (ev *Evaluator) eval(ast AST) {
 	ast.eval(ev)
 }