1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
// 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 any, limit ...any) ([]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
}
// FindRESubmatch returns a slice of all successive matches of the regular
// expression in content. Each element is a slice of strings holding the text
// of the leftmost match of the regular expression and the matches, if any, of
// its subexpressions.
//
// By default all matches will be included. The number of matches can be
// limited with the optional limit parameter. A return value of nil indicates
// no match.
func (ns *Namespace) FindRESubmatch(expr string, content any, limit ...any) ([][]string, error) {
re, err := reCache.Get(expr)
if err != nil {
return nil, err
}
conv, err := cast.ToStringE(content)
if err != nil {
return nil, err
}
n := -1
if len(limit) > 0 {
n, err = cast.ToIntE(limit[0])
if err != nil {
return nil, err
}
}
return re.FindAllStringSubmatch(conv, n), nil
}
// ReplaceRE returns a copy of s, replacing all matches of the regular
// expression pattern with the replacement text repl. The number of replacements
// can be limited with an optional fourth parameter.
func (ns *Namespace) ReplaceRE(pattern, repl, s any, n ...any) (_ 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
}
nn := -1
if len(n) > 0 {
nn, err = cast.ToIntE(n[0])
if err != nil {
return
}
}
re, err := reCache.Get(sp)
if err != nil {
return "", err
}
return re.ReplaceAllStringFunc(ss, func(str string) string {
if nn == 0 {
return str
}
nn -= 1
return re.ReplaceAllString(str, 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)}
|
