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
|
// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
// Package opt defines optional types.
package opt
import (
"fmt"
"strconv"
)
// Bool represents an optional boolean to be JSON-encoded. The string
// is either "true", "false", or the empty string to mean unset.
//
// As a special case, the underlying string may also be the string
// "unset" as as a synonym for the empty string. This lets the
// explicit unset value be exchanged over an encoding/json "omitempty"
// field without it being dropped.
type Bool string
const (
// True is the encoding of an explicit true.
True = Bool("true")
// False is the encoding of an explicit false.
False = Bool("false")
// ExplicitlyUnset is the encoding used by a null
// JSON value. It is a synonym for the empty string.
ExplicitlyUnset = Bool("unset")
// Empty means the Bool is unset and it's neither
// true nor false.
Empty = Bool("")
)
// NewBool constructs a new Bool value equal to b. The returned Bool is set,
// unless Set("") or Clear() methods are called.
func NewBool(b bool) Bool {
return Bool(strconv.FormatBool(b))
}
func (b *Bool) Set(v bool) {
*b = Bool(strconv.FormatBool(v))
}
func (b *Bool) Clear() { *b = "" }
func (b Bool) Get() (v bool, ok bool) {
switch b {
case "true":
return true, true
case "false":
return false, true
default:
return false, false
}
}
// Scan implements database/sql.Scanner.
func (b *Bool) Scan(src any) error {
if src == nil {
*b = ""
return nil
}
switch src := src.(type) {
case bool:
if src {
*b = True
} else {
*b = False
}
return nil
case int64:
if src == 0 {
*b = False
} else {
*b = True
}
return nil
default:
return fmt.Errorf("opt.Bool.Scan: invalid type %T: %v", src, src)
}
}
// Normalized returns the normalized form of b, mapping "unset" to ""
// and leaving other values unchanged.
func (b Bool) Normalized() Bool {
switch b {
case ExplicitlyUnset:
return Empty
default:
return b
}
}
// EqualBool reports whether b is equal to v.
// If b is empty or not a valid bool, it reports false.
func (b Bool) EqualBool(v bool) bool {
p, ok := b.Get()
return ok && p == v
}
var (
trueBytes = []byte(True)
falseBytes = []byte(False)
nullBytes = []byte("null")
)
func (b Bool) MarshalJSON() ([]byte, error) {
switch b {
case True:
return trueBytes, nil
case False:
return falseBytes, nil
case Empty, ExplicitlyUnset:
return nullBytes, nil
}
return nil, fmt.Errorf("invalid opt.Bool value %q", string(b))
}
func (b *Bool) UnmarshalJSON(j []byte) error {
switch string(j) {
case "true":
*b = True
case "false":
*b = False
case "null":
*b = ExplicitlyUnset
default:
return fmt.Errorf("invalid opt.Bool value %q", j)
}
return nil
}
// BoolFlag is a wrapper for Bool that implements [flag.Value].
type BoolFlag struct {
*Bool
}
// Set the value of b, using any value supported by [strconv.ParseBool].
func (b *BoolFlag) Set(s string) error {
v, err := strconv.ParseBool(s)
if err != nil {
return err
}
b.Bool.Set(v)
return nil
}
// String returns "true" or "false" if the value is set, or an empty string otherwise.
func (b *BoolFlag) String() string {
if b == nil || b.Bool == nil {
return ""
}
if v, ok := b.Bool.Get(); ok {
return strconv.FormatBool(v)
}
return ""
}
|
