hugo/tpl/strings/regexp.go
Cameron Moore de7c32a1a8 tpl: Add template function namespaces
This commit moves almost all of the template functions into separate
packages under tpl/ and adds a namespace framework.  All changes should
be backward compatible for end users, as all existing function names in
the template funcMap are left intact.

Seq and DoArithmatic have been moved out of the helpers package and into
template namespaces.

Most of the tests involved have been refactored, and many new tests have
been written.  There's still work to do, but this is a big improvement.

I got a little overzealous and added some new functions along the way:

- strings.Contains
- strings.ContainsAny
- strings.HasSuffix
- strings.TrimPrefix
- strings.TrimSuffix

Documentation is forthcoming.

Fixes #3042
2017-04-30 10:56:38 +02:00

109 lines
2.6 KiB
Go

// Copyright 2017 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package strings
import (
"regexp"
"sync"
"github.com/spf13/cast"
)
// FindRE returns a list of strings that match the regular expression. By default all matches
// will be included. The number of matches can be limited with an optional third parameter.
func (ns *Namespace) FindRE(expr string, content interface{}, limit ...interface{}) ([]string, error) {
re, err := reCache.Get(expr)
if err != nil {
return nil, err
}
conv, err := cast.ToStringE(content)
if err != nil {
return nil, err
}
if len(limit) == 0 {
return re.FindAllString(conv, -1), nil
}
lim, err := cast.ToIntE(limit[0])
if err != nil {
return nil, err
}
return re.FindAllString(conv, lim), nil
}
// ReplaceRE returns a copy of s, replacing all matches of the regular
// expression pattern with the replacement text repl.
func (ns *Namespace) ReplaceRE(pattern, repl, s interface{}) (_ string, err error) {
sp, err := cast.ToStringE(pattern)
if err != nil {
return
}
sr, err := cast.ToStringE(repl)
if err != nil {
return
}
ss, err := cast.ToStringE(s)
if err != nil {
return
}
re, err := reCache.Get(sp)
if err != nil {
return "", err
}
return re.ReplaceAllString(ss, sr), nil
}
// regexpCache represents a cache of regexp objects protected by a mutex.
type regexpCache struct {
mu sync.RWMutex
re map[string]*regexp.Regexp
}
// Get retrieves a regexp object from the cache based upon the pattern.
// If the pattern is not found in the cache, create one
func (rc *regexpCache) Get(pattern string) (re *regexp.Regexp, err error) {
var ok bool
if re, ok = rc.get(pattern); !ok {
re, err = regexp.Compile(pattern)
if err != nil {
return nil, err
}
rc.set(pattern, re)
}
return re, nil
}
func (rc *regexpCache) get(key string) (re *regexp.Regexp, ok bool) {
rc.mu.RLock()
re, ok = rc.re[key]
rc.mu.RUnlock()
return
}
func (rc *regexpCache) set(key string, re *regexp.Regexp) {
rc.mu.Lock()
rc.re[key] = re
rc.mu.Unlock()
}
var reCache = regexpCache{re: make(map[string]*regexp.Regexp)}