rss-tools/vendor/golang.org/x/text/internal/language/compact/compact.go (view raw)
| 1 | // Copyright 2018 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // Package compact defines a compact representation of language tags. |
| 6 | // |
| 7 | // Common language tags (at least all for which locale information is defined |
| 8 | // in CLDR) are assigned a unique index. Each Tag is associated with such an |
| 9 | // ID for selecting language-related resources (such as translations) as well |
| 10 | // as one for selecting regional defaults (currency, number formatting, etc.) |
| 11 | // |
| 12 | // It may want to export this functionality at some point, but at this point |
| 13 | // this is only available for use within x/text. |
| 14 | package compact // import "golang.org/x/text/internal/language/compact" |
| 15 | |
| 16 | import ( |
| 17 | "sort" |
| 18 | "strings" |
| 19 | |
| 20 | "golang.org/x/text/internal/language" |
| 21 | ) |
| 22 | |
| 23 | // ID is an integer identifying a single tag. |
| 24 | type ID uint16 |
| 25 | |
| 26 | func getCoreIndex(t language.Tag) (id ID, ok bool) { |
| 27 | cci, ok := language.GetCompactCore(t) |
| 28 | if !ok { |
| 29 | return 0, false |
| 30 | } |
| 31 | i := sort.Search(len(coreTags), func(i int) bool { |
| 32 | return cci <= coreTags[i] |
| 33 | }) |
| 34 | if i == len(coreTags) || coreTags[i] != cci { |
| 35 | return 0, false |
| 36 | } |
| 37 | return ID(i), true |
| 38 | } |
| 39 | |
| 40 | // Parent returns the ID of the parent or the root ID if id is already the root. |
| 41 | func (id ID) Parent() ID { |
| 42 | return parents[id] |
| 43 | } |
| 44 | |
| 45 | // Tag converts id to an internal language Tag. |
| 46 | func (id ID) Tag() language.Tag { |
| 47 | if int(id) >= len(coreTags) { |
| 48 | return specialTags[int(id)-len(coreTags)] |
| 49 | } |
| 50 | return coreTags[id].Tag() |
| 51 | } |
| 52 | |
| 53 | var specialTags []language.Tag |
| 54 | |
| 55 | func init() { |
| 56 | tags := strings.Split(specialTagsStr, " ") |
| 57 | specialTags = make([]language.Tag, len(tags)) |
| 58 | for i, t := range tags { |
| 59 | specialTags[i] = language.MustParse(t) |
| 60 | } |
| 61 | } |