blob: 7f524d239539e05c4d444e822dbefcb57d5a2446 [file] [log] [blame]
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package lazyregexp is a thin wrapper over regexp, allowing the use of global
// regexp variables without forcing them to be compiled at init.
package lazyregexp
import (
// Regexp is a wrapper around regexp.Regexp, where the underlying regexp will be
// compiled the first time it is needed.
type Regexp struct {
str string
once sync.Once
rx *regexp.Regexp
func (r *Regexp) re() *regexp.Regexp {
return r.rx
func (r *Regexp) build() {
r.rx = regexp.MustCompile(r.str)
r.str = ""
func (r *Regexp) MatchString(s string) bool {
var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test")
// New creates a new lazy regexp, delaying the compiling work until it is first
// needed. If the code is being run as part of tests, the regexp compiling will
// happen immediately.
func New(str string) *Regexp {
lr := &Regexp{str: str}
if inTest {
// In tests, always compile the regexps early.
return lr