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
|
// Copyright (C) 2022-2023 Luke Shumaker <lukeshu@lukeshu.com>
//
// SPDX-License-Identifier: GPL-2.0-or-later
package containers
import (
"fmt"
"io"
"sort"
"git.lukeshu.com/go/lowmemjson"
"git.lukeshu.com/btrfs-progs-ng/lib/maps"
)
// Set[T] is an unordered set of T.
type Set[T comparable] map[T]struct{}
var (
_ lowmemjson.Encodable = Set[int]{}
_ lowmemjson.Decodable = (*Set[int])(nil)
)
func cast[T any](x any) T {
//nolint:forcetypeassert // Only called within a type switch.
return x.(T)
}
func (o Set[T]) EncodeJSON(w io.Writer) error {
var less func(a, b T) bool
var zero T
switch (any(zero)).(type) {
case _Ordered[T]:
less = func(a, b T) bool { return cast[_Ordered[T]](a).Compare(b) < 0 }
// This is the constraints.Ordered list
case string:
less = func(a, b T) bool { return cast[string](a) < cast[string](b) }
case int:
less = func(a, b T) bool { return cast[int](a) < cast[int](b) }
case int8:
less = func(a, b T) bool { return cast[int8](a) < cast[int8](b) }
case int16:
less = func(a, b T) bool { return cast[int16](a) < cast[int16](b) }
case int32:
less = func(a, b T) bool { return cast[int32](a) < cast[int32](b) }
case int64:
less = func(a, b T) bool { return cast[int64](a) < cast[int64](b) }
case uint:
less = func(a, b T) bool { return cast[uint](a) < cast[uint](b) }
case uint8:
less = func(a, b T) bool { return cast[uint8](a) < cast[uint8](b) }
case uint16:
less = func(a, b T) bool { return cast[uint16](a) < cast[uint16](b) }
case uint32:
less = func(a, b T) bool { return cast[uint32](a) < cast[uint32](b) }
case uint64:
less = func(a, b T) bool { return cast[uint64](a) < cast[uint64](b) }
case uintptr:
less = func(a, b T) bool { return cast[uintptr](a) < cast[uintptr](b) }
case float32:
less = func(a, b T) bool { return cast[float32](a) < cast[float32](b) }
case float64:
less = func(a, b T) bool { return cast[float64](a) < cast[float64](b) }
default:
less = func(a, b T) bool { return fmt.Sprint(a) < fmt.Sprint(b) }
}
keys := maps.Keys(o)
sort.Slice(keys, func(i, j int) bool {
return less(keys[i], keys[j])
})
return lowmemjson.NewEncoder(w).Encode(keys)
}
func (o *Set[T]) DecodeJSON(r io.RuneScanner) error {
c, _, _ := r.ReadRune()
if c == 'n' {
_, _, _ = r.ReadRune() // u
_, _, _ = r.ReadRune() // l
_, _, _ = r.ReadRune() // l
*o = nil
return nil
}
_ = r.UnreadRune()
*o = Set[T]{}
return lowmemjson.DecodeArray(r, func(r io.RuneScanner) error {
var val T
if err := lowmemjson.NewDecoder(r).Decode(&val); err != nil {
return err
}
(*o)[val] = struct{}{}
return nil
})
}
func NewSet[T comparable](values ...T) Set[T] {
ret := make(Set[T], len(values))
for _, value := range values {
ret.Insert(value)
}
return ret
}
func (o Set[T]) Insert(v T) {
o[v] = struct{}{}
}
func (o Set[T]) InsertFrom(p Set[T]) {
for v := range p {
o[v] = struct{}{}
}
}
func (o Set[T]) Delete(v T) {
if o == nil {
return
}
delete(o, v)
}
func (o Set[T]) DeleteFrom(p Set[T]) {
if o == nil {
return
}
for v := range p {
delete(o, v)
}
}
func (o Set[T]) TakeOne() T {
for v := range o {
return v
}
var zero T
return zero
}
func (o Set[T]) Has(v T) bool {
_, has := o[v]
return has
}
func (small Set[T]) HasAny(big Set[T]) bool {
if len(big) < len(small) {
small, big = big, small
}
for v := range small {
if _, ok := big[v]; ok {
return true
}
}
return false
}
func (small Set[T]) Intersection(big Set[T]) Set[T] {
if len(big) < len(small) {
small, big = big, small
}
ret := make(Set[T])
for v := range small {
if _, ok := big[v]; ok {
ret.Insert(v)
}
}
return ret
}
|
