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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
// Copyright 2013 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 language
import "errors"
type scriptRegionFlags uint8
const (
isList = 1 << iota
scriptInFrom
regionInFrom
)
func (t *Tag) setUndefinedLang(id Language) {
if t.LangID == 0 {
t.LangID = id
}
}
func (t *Tag) setUndefinedScript(id Script) {
if t.ScriptID == 0 {
t.ScriptID = id
}
}
func (t *Tag) setUndefinedRegion(id Region) {
if t.RegionID == 0 || t.RegionID.Contains(id) {
t.RegionID = id
}
}
// ErrMissingLikelyTagsData indicates no information was available
// to compute likely values of missing tags.
var ErrMissingLikelyTagsData = errors.New("missing likely tags data")
// addLikelySubtags sets subtags to their most likely value, given the locale.
// In most cases this means setting fields for unknown values, but in some
// cases it may alter a value. It returns an ErrMissingLikelyTagsData error
// if the given locale cannot be expanded.
func (t Tag) addLikelySubtags() (Tag, error) {
id, err := addTags(t)
if err != nil {
return t, err
} else if id.equalTags(t) {
return t, nil
}
id.RemakeString()
return id, nil
}
// specializeRegion attempts to specialize a group region.
func specializeRegion(t *Tag) bool {
if i := regionInclusion[t.RegionID]; i < nRegionGroups {
x := likelyRegionGroup[i]
if Language(x.lang) == t.LangID && Script(x.script) == t.ScriptID {
t.RegionID = Region(x.region)
}
return true
}
return false
}
// Maximize returns a new tag with missing tags filled in.
func (t Tag) Maximize() (Tag, error) {
return addTags(t)
}
func addTags(t Tag) (Tag, error) {
// We leave private use identifiers alone.
if t.IsPrivateUse() {
return t, nil
}
if t.ScriptID != 0 && t.RegionID != 0 {
if t.LangID != 0 {
// already fully specified
specializeRegion(&t)
return t, nil
}
// Search matches for und-script-region. Note that for these cases
// region will never be a group so there is no need to check for this.
list := likelyRegion[t.RegionID : t.RegionID+1]
if x := list[0]; x.flags&isList != 0 {
list = likelyRegionList[x.lang : x.lang+uint16(x.script)]
}
for _, x := range list {
// Deviating from the spec. See match_test.go for details.
if Script(x.script) == t.ScriptID {
t.setUndefinedLang(Language(x.lang))
return t, nil
}
}
}
if t.LangID != 0 {
// Search matches for lang-script and lang-region, where lang != und.
if t.LangID < langNoIndexOffset {
x := likelyLang[t.LangID]
if x.flags&isList != 0 {
list := likelyLangList[x.region : x.region+uint16(x.script)]
if t.ScriptID != 0 {
for _, x := range list {
if Script(x.script) == t.ScriptID && x.flags&scriptInFrom != 0 {
t.setUndefinedRegion(Region(x.region))
return t, nil
}
}
} else if t.RegionID != 0 {
count := 0
goodScript := true
tt := t
for _, x := range list {
// We visit all entries for which the script was not
// defined, including the ones where the region was not
// defined. This allows for proper disambiguation within
// regions.
if x.flags&scriptInFrom == 0 && t.RegionID.Contains(Region(x.region)) {
tt.RegionID = Region(x.region)
tt.setUndefinedScript(Script(x.script))
goodScript = goodScript && tt.ScriptID == Script(x.script)
count++
}
}
if count == 1 {
return tt, nil
}
// Even if we fail to find a unique Region, we might have
// an unambiguous script.
if goodScript {
t.ScriptID = tt.ScriptID
}
}
}
}
} else {
// Search matches for und-script.
if t.ScriptID != 0 {
x := likelyScript[t.ScriptID]
if x.region != 0 {
t.setUndefinedRegion(Region(x.region))
t.setUndefinedLang(Language(x.lang))
return t, nil
}
}
// Search matches for und-region. If und-script-region exists, it would
// have been found earlier.
if t.RegionID != 0 {
if i := regionInclusion[t.RegionID]; i < nRegionGroups {
x := likelyRegionGroup[i]
if x.region != 0 {
t.setUndefinedLang(Language(x.lang))
t.setUndefinedScript(Script(x.script))
t.RegionID = Region(x.region)
}
} else {
x := likelyRegion[t.RegionID]
if x.flags&isList != 0 {
x = likelyRegionList[x.lang]
}
if x.script != 0 && x.flags != scriptInFrom {
t.setUndefinedLang(Language(x.lang))
t.setUndefinedScript(Script(x.script))
return t, nil
}
}
}
}
// Search matches for lang.
if t.LangID < langNoIndexOffset {
x := likelyLang[t.LangID]
if x.flags&isList != 0 {
x = likelyLangList[x.region]
}
if x.region != 0 {
t.setUndefinedScript(Script(x.script))
t.setUndefinedRegion(Region(x.region))
}
specializeRegion(&t)
if t.LangID == 0 {
t.LangID = _en // default language
}
return t, nil
}
return t, ErrMissingLikelyTagsData
}
func (t *Tag) setTagsFrom(id Tag) {
t.LangID = id.LangID
t.ScriptID = id.ScriptID
t.RegionID = id.RegionID
}
// minimize removes the region or script subtags from t such that
// t.addLikelySubtags() == t.minimize().addLikelySubtags().
func (t Tag) minimize() (Tag, error) {
t, err := minimizeTags(t)
if err != nil {
return t, err
}
t.RemakeString()
return t, nil
}
// minimizeTags mimics the behavior of the ICU 51 C implementation.
func minimizeTags(t Tag) (Tag, error) {
if t.equalTags(Und) {
return t, nil
}
max, err := addTags(t)
if err != nil {
return t, err
}
for _, id := range [...]Tag{
{LangID: t.LangID},
{LangID: t.LangID, RegionID: t.RegionID},
{LangID: t.LangID, ScriptID: t.ScriptID},
} {
if x, err := addTags(id); err == nil && max.equalTags(x) {
t.setTagsFrom(id)
break
}
}
return t, nil
}
|
