-
Notifications
You must be signed in to change notification settings - Fork 53
/
Copy pathsets.go
195 lines (171 loc) · 4.45 KB
/
sets.go
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
// Copyright 2020 Lingfei Kong <[email protected]>. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.
package errors
import (
"reflect"
"sort"
)
// Empty is public since it is used by some internal API objects for conversions between external
// string arrays and internal sets, and conversion logic requires public types today.
type Empty struct{}
// String is a set of strings, implemented via map[string]struct{} for minimal memory consumption.
type String map[string]Empty
// NewString creates a String from a list of values.
func NewString(items ...string) String {
ss := String{}
ss.Insert(items...)
return ss
}
// StringKeySet creates a String from a keys of a map[string](? extends interface{}).
// If the value passed in is not actually a map, this will panic.
func StringKeySet(theMap interface{}) String {
v := reflect.ValueOf(theMap)
ret := String{}
for _, keyValue := range v.MapKeys() {
ret.Insert(keyValue.Interface().(string))
}
return ret
}
// Insert adds items to the set.
func (s String) Insert(items ...string) String {
for _, item := range items {
s[item] = Empty{}
}
return s
}
// Delete removes all items from the set.
func (s String) Delete(items ...string) String {
for _, item := range items {
delete(s, item)
}
return s
}
// Has returns true if and only if item is contained in the set.
func (s String) Has(item string) bool {
_, contained := s[item]
return contained
}
// HasAll returns true if and only if all items are contained in the set.
func (s String) HasAll(items ...string) bool {
for _, item := range items {
if !s.Has(item) {
return false
}
}
return true
}
// HasAny returns true if any items are contained in the set.
func (s String) HasAny(items ...string) bool {
for _, item := range items {
if s.Has(item) {
return true
}
}
return false
}
// Difference returns a set of objects that are not in s2
// For example:
// s = {a1, a2, a3}
// s2 = {a1, a2, a4, a5}
// s.Difference(s2) = {a3}
// s2.Difference(s) = {a4, a5}
func (s String) Difference(s2 String) String {
result := NewString()
for key := range s {
if !s2.Has(key) {
result.Insert(key)
}
}
return result
}
// Union returns a new set which includes items in either s or s2.
// For example:
// s = {a1, a2}
// s2 = {a3, a4}
// s.Union(s2) = {a1, a2, a3, a4}
// s2.Union(s) = {a1, a2, a3, a4}
func (s String) Union(s2 String) String {
result := NewString()
for key := range s {
result.Insert(key)
}
for key := range s2 {
result.Insert(key)
}
return result
}
// Intersection returns a new set which includes the item in BOTH s and s2
// For example:
// s = {a1, a2}
// s2 = {a2, a3}
// s.Intersection(s2) = {a2}
func (s String) Intersection(s2 String) String {
var walk, other String
result := NewString()
if s.Len() < s2.Len() {
walk = s
other = s2
} else {
walk = s2
other = s
}
for key := range walk {
if other.Has(key) {
result.Insert(key)
}
}
return result
}
// IsSuperset returns true if and only if s is a superset of s2.
func (s String) IsSuperset(s2 String) bool {
for item := range s2 {
if !s.Has(item) {
return false
}
}
return true
}
// Equal returns true if and only if s is equal (as a set) to s2.
// Two sets are equal if their membership is identical.
// (In practice, this means same elements, order doesn't matter)
func (s String) Equal(s2 String) bool {
return len(s) == len(s2) && s.IsSuperset(s2)
}
type sortableSliceOfString []string
func (s sortableSliceOfString) Len() int { return len(s) }
func (s sortableSliceOfString) Less(i, j int) bool { return lessString(s[i], s[j]) }
func (s sortableSliceOfString) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
// List returns the contents as a sorted string slice.
func (s String) List() []string {
res := make(sortableSliceOfString, 0, len(s))
for key := range s {
res = append(res, key)
}
sort.Sort(res)
return []string(res)
}
// UnsortedList returns the slice with contents in random order.
func (s String) UnsortedList() []string {
res := make([]string, 0, len(s))
for key := range s {
res = append(res, key)
}
return res
}
// PopAny returns a single element from the set.
func (s String) PopAny() (string, bool) {
for key := range s {
s.Delete(key)
return key, true
}
var zeroValue string
return zeroValue, false
}
// Len returns the size of the set.
func (s String) Len() int {
return len(s)
}
func lessString(lhs, rhs string) bool {
return lhs < rhs
}