_, err := ParseFile(token.NewFileSet(), "", src, 0)
	if err == nil {
		t.Errorf("ParseFile(%s) succeeded unexpectedly", src)
	}
}

func TestParseExprFrom(t *testing.T) {
	src := "s[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]+\ns[::]"
	_, err := ParseExprFrom(token.NewFileSet(), "", src, 0)
	if err == nil {