dict.go

Documentation: golang.org/x/text/message/catalog

     1  // Copyright 2017 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 catalog
     6  
     7  import (
     8  	"sync"
     9  
    10  	"golang.org/x/text/internal"
    11  	"golang.org/x/text/internal/catmsg"
    12  	"golang.org/x/text/language"
    13  )
    14  
    15  // TODO:
    16  // Dictionary returns a Dictionary that returns the first Message, using the
    17  // given language tag, that matches:
    18  //   1. the last one registered by one of the Set methods
    19  //   2. returned by one of the Loaders
    20  //   3. repeat from 1. using the parent language
    21  // This approach allows messages to be underspecified.
    22  // func (c *Catalog) Dictionary(tag language.Tag) (Dictionary, error) {
    23  // 	// TODO: verify dictionary exists.
    24  // 	return &dict{&c.index, tag}, nil
    25  // }
    26  
    27  type dict struct {
    28  	s   *store
    29  	tag language.Tag // TODO: make compact tag.
    30  }
    31  
    32  func (d *dict) Lookup(key string) (data string, ok bool) {
    33  	return d.s.lookup(d.tag, key)
    34  }
    35  
    36  func (b *Builder) lookup(tag language.Tag, key string) (data string, ok bool) {
    37  	return b.index.lookup(tag, key)
    38  }
    39  
    40  func (c *Builder) set(tag language.Tag, key string, s *store, msg ...Message) error {
    41  	data, err := catmsg.Compile(tag, &dict{&c.macros, tag}, firstInSequence(msg))
    42  
    43  	s.mutex.Lock()
    44  	defer s.mutex.Unlock()
    45  
    46  	m := s.index[tag]
    47  	if m == nil {
    48  		m = msgMap{}
    49  		if s.index == nil {
    50  			s.index = map[language.Tag]msgMap{}
    51  		}
    52  		c.matcher = nil
    53  		s.index[tag] = m
    54  	}
    55  
    56  	m[key] = data
    57  	return err
    58  }
    59  
    60  func (c *Builder) Matcher() language.Matcher {
    61  	c.index.mutex.RLock()
    62  	m := c.matcher
    63  	c.index.mutex.RUnlock()
    64  	if m != nil {
    65  		return m
    66  	}
    67  
    68  	c.index.mutex.Lock()
    69  	if c.matcher == nil {
    70  		c.matcher = language.NewMatcher(c.unlockedLanguages())
    71  	}
    72  	m = c.matcher
    73  	c.index.mutex.Unlock()
    74  	return m
    75  }
    76  
    77  type store struct {
    78  	mutex sync.RWMutex
    79  	index map[language.Tag]msgMap
    80  }
    81  
    82  type msgMap map[string]string
    83  
    84  func (s *store) lookup(tag language.Tag, key string) (data string, ok bool) {
    85  	s.mutex.RLock()
    86  	defer s.mutex.RUnlock()
    87  
    88  	for ; ; tag = tag.Parent() {
    89  		if msgs, ok := s.index[tag]; ok {
    90  			if msg, ok := msgs[key]; ok {
    91  				return msg, true
    92  			}
    93  		}
    94  		if tag == language.Und {
    95  			break
    96  		}
    97  	}
    98  	return "", false
    99  }
   100  
   101  // Languages returns all languages for which the Catalog contains variants.
   102  func (b *Builder) Languages() []language.Tag {
   103  	s := &b.index
   104  	s.mutex.RLock()
   105  	defer s.mutex.RUnlock()
   106  
   107  	return b.unlockedLanguages()
   108  }
   109  
   110  func (b *Builder) unlockedLanguages() []language.Tag {
   111  	s := &b.index
   112  	if len(s.index) == 0 {
   113  		return nil
   114  	}
   115  	tags := make([]language.Tag, 0, len(s.index))
   116  	_, hasFallback := s.index[b.options.fallback]
   117  	offset := 0
   118  	if hasFallback {
   119  		tags = append(tags, b.options.fallback)
   120  		offset = 1
   121  	}
   122  	for t := range s.index {
   123  		if t != b.options.fallback {
   124  			tags = append(tags, t)
   125  		}
   126  	}
   127  	internal.SortTags(tags[offset:])
   128  	return tags
   129  }
   130
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