68 lines
1.9 KiB
Go
68 lines
1.9 KiB
Go
|
// Copyright 2015 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 internal
|
||
|
|
|
||
|
|
// This file contains matchers that implement CLDR inheritance.
|
||
|
|
//
|
||
|
|
// See https://unicode.org/reports/tr35/#Locale_Inheritance.
|
||
|
|
//
|
||
|
|
// Some of the inheritance described in this document is already handled by
|
||
|
|
// the cldr package.
|
||
|
|
|
||
|
|
import (
|
||
|
|
"golang.org/x/text/language"
|
||
|
|
)
|
||
|
|
|
||
|
|
// TODO: consider if (some of the) matching algorithm needs to be public after
|
||
|
|
// getting some feel about what is generic and what is specific.
|
||
|
|
|
||
|
|
// NewInheritanceMatcher returns a matcher that matches based on the inheritance
|
||
|
|
// chain.
|
||
|
|
//
|
||
|
|
// The matcher uses canonicalization and the parent relationship to find a
|
||
|
|
// match. The resulting match will always be either Und or a language with the
|
||
|
|
// same language and script as the requested language. It will not match
|
||
|
|
// languages for which there is understood to be mutual or one-directional
|
||
|
|
// intelligibility.
|
||
|
|
//
|
||
|
|
// A Match will indicate an Exact match if the language matches after
|
||
|
|
// canonicalization and High if the matched tag is a parent.
|
||
|
|
func NewInheritanceMatcher(t []language.Tag) *InheritanceMatcher {
|
||
|
|
tags := &InheritanceMatcher{make(map[language.Tag]int)}
|
||
|
|
for i, tag := range t {
|
||
|
|
ct, err := language.All.Canonicalize(tag)
|
||
|
|
if err != nil {
|
||
|
|
ct = tag
|
||
|
|
}
|
||
|
|
tags.index[ct] = i
|
||
|
|
}
|
||
|
|
return tags
|
||
|
|
}
|
||
|
|
|
||
|
|
type InheritanceMatcher struct {
|
||
|
|
index map[language.Tag]int
|
||
|
|
}
|
||
|
|
|
||
|
|
func (m InheritanceMatcher) Match(want ...language.Tag) (language.Tag, int, language.Confidence) {
|
||
|
|
for _, t := range want {
|
||
|
|
ct, err := language.All.Canonicalize(t)
|
||
|
|
if err != nil {
|
||
|
|
ct = t
|
||
|
|
}
|
||
|
|
conf := language.Exact
|
||
|
|
for {
|
||
|
|
if index, ok := m.index[ct]; ok {
|
||
|
|
return ct, index, conf
|
||
|
|
}
|
||
|
|
if ct == language.Und {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
ct = ct.Parent()
|
||
|
|
conf = language.High
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return language.Und, 0, language.No
|
||
|
|
}
|