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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
// Copyright 2019 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 strs provides string manipulation functionality specific to protobuf.
package strs
import (
"go/token"
"strings"
"unicode"
"unicode/utf8"
"google.golang.org/protobuf/internal/flags"
"google.golang.org/protobuf/reflect/protoreflect"
)
// EnforceUTF8 reports whether to enforce strict UTF-8 validation.
func EnforceUTF8(fd protoreflect.FieldDescriptor) bool {
if flags.ProtoLegacy {
if fd, ok := fd.(interface{ EnforceUTF8() bool }); ok {
return fd.EnforceUTF8()
}
}
return fd.Syntax() == protoreflect.Proto3
}
// GoCamelCase camel-cases a protobuf name for use as a Go identifier.
//
// If there is an interior underscore followed by a lower case letter,
// drop the underscore and convert the letter to upper case.
func GoCamelCase(s string) string {
// Invariant: if the next letter is lower case, it must be converted
// to upper case.
// That is, we process a word at a time, where words are marked by _ or
// upper case letter. Digits are treated as words.
var b []byte
for i := 0; i < len(s); i++ {
c := s[i]
switch {
case c == '.' && i+1 < len(s) && isASCIILower(s[i+1]):
// Skip over '.' in ".{{lowercase}}".
case c == '.':
b = append(b, '_') // convert '.' to '_'
case c == '_' && (i == 0 || s[i-1] == '.'):
// Convert initial '_' to ensure we start with a capital letter.
// Do the same for '_' after '.' to match historic behavior.
b = append(b, 'X') // convert '_' to 'X'
case c == '_' && i+1 < len(s) && isASCIILower(s[i+1]):
// Skip over '_' in "_{{lowercase}}".
case isASCIIDigit(c):
b = append(b, c)
default:
// Assume we have a letter now - if not, it's a bogus identifier.
// The next word is a sequence of characters that must start upper case.
if isASCIILower(c) {
c -= 'a' - 'A' // convert lowercase to uppercase
}
b = append(b, c)
// Accept lower case sequence that follows.
for ; i+1 < len(s) && isASCIILower(s[i+1]); i++ {
b = append(b, s[i+1])
}
}
}
return string(b)
}
// GoSanitized converts a string to a valid Go identifier.
func GoSanitized(s string) string {
// Sanitize the input to the set of valid characters,
// which must be '_' or be in the Unicode L or N categories.
s = strings.Map(func(r rune) rune {
if unicode.IsLetter(r) || unicode.IsDigit(r) {
return r
}
return '_'
}, s)
// Prepend '_' in the event of a Go keyword conflict or if
// the identifier is invalid (does not start in the Unicode L category).
r, _ := utf8.DecodeRuneInString(s)
if token.Lookup(s).IsKeyword() || !unicode.IsLetter(r) {
return "_" + s
}
return s
}
// JSONCamelCase converts a snake_case identifier to a camelCase identifier,
// according to the protobuf JSON specification.
func JSONCamelCase(s string) string {
var b []byte
var wasUnderscore bool
for i := 0; i < len(s); i++ { // proto identifiers are always ASCII
c := s[i]
if c != '_' {
if wasUnderscore && isASCIILower(c) {
c -= 'a' - 'A' // convert to uppercase
}
b = append(b, c)
}
wasUnderscore = c == '_'
}
return string(b)
}
// JSONSnakeCase converts a camelCase identifier to a snake_case identifier,
// according to the protobuf JSON specification.
func JSONSnakeCase(s string) string {
var b []byte
for i := 0; i < len(s); i++ { // proto identifiers are always ASCII
c := s[i]
if isASCIIUpper(c) {
b = append(b, '_')
c += 'a' - 'A' // convert to lowercase
}
b = append(b, c)
}
return string(b)
}
// MapEntryName derives the name of the map entry message given the field name.
// See protoc v3.8.0: src/google/protobuf/descriptor.cc:254-276,6057
func MapEntryName(s string) string {
var b []byte
upperNext := true
for _, c := range s {
switch {
case c == '_':
upperNext = true
case upperNext:
b = append(b, byte(unicode.ToUpper(c)))
upperNext = false
default:
b = append(b, byte(c))
}
}
b = append(b, "Entry"...)
return string(b)
}
// EnumValueName derives the camel-cased enum value name.
// See protoc v3.8.0: src/google/protobuf/descriptor.cc:297-313
func EnumValueName(s string) string {
var b []byte
upperNext := true
for _, c := range s {
switch {
case c == '_':
upperNext = true
case upperNext:
b = append(b, byte(unicode.ToUpper(c)))
upperNext = false
default:
b = append(b, byte(unicode.ToLower(c)))
upperNext = false
}
}
return string(b)
}
// TrimEnumPrefix trims the enum name prefix from an enum value name,
// where the prefix is all lowercase without underscores.
// See protoc v3.8.0: src/google/protobuf/descriptor.cc:330-375
func TrimEnumPrefix(s, prefix string) string {
s0 := s // original input
for len(s) > 0 && len(prefix) > 0 {
if s[0] == '_' {
s = s[1:]
continue
}
if unicode.ToLower(rune(s[0])) != rune(prefix[0]) {
return s0 // no prefix match
}
s, prefix = s[1:], prefix[1:]
}
if len(prefix) > 0 {
return s0 // no prefix match
}
s = strings.TrimLeft(s, "_")
if len(s) == 0 {
return s0 // avoid returning empty string
}
return s
}
func isASCIILower(c byte) bool {
return 'a' <= c && c <= 'z'
}
func isASCIIUpper(c byte) bool {
return 'A' <= c && c <= 'Z'
}
func isASCIIDigit(c byte) bool {
return '0' <= c && c <= '9'
}
|
