# class ActiveSupport::Inflector::Inflections

A singleton instance of this class is yielded by ActiveSupport::Inflector#inflections, which can then be used to specify additional inflection rules. Examples:

    ActiveSupport::Inflector.inflections do |inflect|
      inflect.plural %r^(ox)$/, '\1\2en'
      inflect.singular %r^(ox)en/, '\1'

      inflect.irregular 'octopus', 'octopi'

      inflect.uncountable "equipment"
    end

New rules are added at the top. So in the example above, the irregular rule for octopus will now be the first of the pluralization and singularization rules that is runs. This guarantees that your rules run before any of the rules that may already have been loaded.

### Attributes

acronym_regex[R]
acronyms[R]
humans[R]
plurals[R]
singulars[R]
uncountables[R]

### Public Class Methods

instance() click to toggle source

    # File lib/active_support/inflector/inflections.rb, line 19
    def self.instance
      @__instance__ ||= new
    end

new() click to toggle source

    # File lib/active_support/inflector/inflections.rb, line 25
    def initialize
      @plurals, @singulars, @uncountables, @humans, @acronyms, @acronym_regex = [], [], [], [], {}, %r(?=a)b/
    end

### Public Instance Methods

acronym(word) click to toggle source

Specifies a new acronym. An acronym must be specified as it will appear in a camelized string. An underscore string that contains the acronym will retain the acronym when passed to `camelize`, `humanize`, or `titleize`. A camelized string that contains the acronym will maintain the acronym when titleized or humanized, and will convert the acronym into a non-delimited single lowercase word when passed to `underscore`.

Examples:

    acronym 'HTML'
    titleize 'html' #=> 'HTML'
    camelize 'html' #=> 'HTML'
    underscore 'MyHTML' #=> 'my_html'

The acronym, however, must occur as a delimited unit and not be part of another word for conversions to recognize it:

    acronym 'HTTP'
    camelize 'my_http_delimited' #=> 'MyHTTPDelimited'
    camelize 'https' #=> 'Https', not 'HTTPs'
    underscore 'HTTPS' #=> 'http_s', not 'https'

    acronym 'HTTPS'
    camelize 'https' #=> 'HTTPS'
    underscore 'HTTPS' #=> 'https'

Note: Acronyms that are passed to `pluralize` will no longer be recognized, since the acronym will not occur as a delimited unit in the pluralized result. To work around this, you must specify the pluralized form as an acronym as well:

    acronym 'API'
    camelize(pluralize('api')) #=> 'Apis'

    acronym 'APIs'
    camelize(pluralize('api')) #=> 'APIs'

`acronym` may be used to specify any word that contains an acronym or otherwise needs to maintain a non-standard capitalization. The only restriction is that the word must begin with a capital letter.

Examples:

    acronym 'RESTful'
    underscore 'RESTful' #=> 'restful'
    underscore 'RESTfulController' #=> 'restful_controller'
    titleize 'RESTfulController' #=> 'RESTful Controller'
    camelize 'restful' #=> 'RESTful'
    camelize 'restful_controller' #=> 'RESTfulController'

    acronym 'McDonald'
    underscore 'McDonald' #=> 'mcdonald'
    camelize 'mcdonald' #=> 'McDonald'

    # File lib/active_support/inflector/inflections.rb, line 75
    def acronym(word)
      @acronyms[word.downcase] = word
      @acronym_regex = %r#{@acronyms.values.join("|")}/
    end

clear(scope = :all) click to toggle source

Clears the loaded inflections within a given scope (default is `:all`). Give the scope as a symbol of the inflection type, the options are: `:plurals`, `:singulars`, `:uncountables`, `:humans`.

Examples:

    clear :all
    clear :plurals

    # File lib/active_support/inflector/inflections.rb, line 147
    def clear(scope = :all)
      case scope
        when :all
          @plurals, @singulars, @uncountables, @humans = [], [], [], []
        else
          instance_variable_set "@#{scope}", []
      end
    end

human(rule, replacement) click to toggle source

Specifies a humanized form of a string by a regular expression rule or by a string mapping. When using a regular expression based replacement, the normal humanize formatting is called after the replacement. When a string is used, the human form should be specified as desired (example: ‘The name’, not ‘the_name’)

Examples:

    human /_cnt$/i, '\1_count'
    human "legacy_col_person_name", "Name"

    # File lib/active_support/inflector/inflections.rb, line 136
    def human(rule, replacement)
      @humans.insert(0, [rule, replacement])
    end

irregular(singular, plural) click to toggle source

Specifies a new irregular that applies to both pluralization and singularization at the same time. This can only be used for strings, not regular expressions. You simply pass the irregular in singular and plural form.

Examples:

    irregular 'octopus', 'octopi'
    irregular 'person', 'people'

    # File lib/active_support/inflector/inflections.rb, line 102
    def irregular(singular, plural)
      @uncountables.delete(singular)
      @uncountables.delete(plural)
      if singular[0,1].upcase == plural[0,1].upcase
        plural(Regexp.new("(#{singular[0,1]})#{singular[1..-1]}$", "i"), '\1' + plural[1..-1])
        plural(Regexp.new("(#{plural[0,1]})#{plural[1..-1]}$", "i"), '\1' + plural[1..-1])
        singular(Regexp.new("(#{plural[0,1]})#{plural[1..-1]}$", "i"), '\1' + singular[1..-1])
      else
        plural(Regexp.new("#{singular[0,1].upcase}(?i)#{singular[1..-1]}$"), plural[0,1].upcase + plural[1..-1])
        plural(Regexp.new("#{singular[0,1].downcase}(?i)#{singular[1..-1]}$"), plural[0,1].downcase + plural[1..-1])
        plural(Regexp.new("#{plural[0,1].upcase}(?i)#{plural[1..-1]}$"), plural[0,1].upcase + plural[1..-1])
        plural(Regexp.new("#{plural[0,1].downcase}(?i)#{plural[1..-1]}$"), plural[0,1].downcase + plural[1..-1])
        singular(Regexp.new("#{plural[0,1].upcase}(?i)#{plural[1..-1]}$"), singular[0,1].upcase + singular[1..-1])
        singular(Regexp.new("#{plural[0,1].downcase}(?i)#{plural[1..-1]}$"), singular[0,1].downcase + singular[1..-1])
      end
    end

plural(rule, replacement) click to toggle source

Specifies a new pluralization rule and its replacement. The rule can either be a string or a regular expression. The replacement should always be a string that may include references to the matched data from the rule.

    # File lib/active_support/inflector/inflections.rb, line 82
    def plural(rule, replacement)
      @uncountables.delete(rule) if rule.is_a?(String)
      @uncountables.delete(replacement)
      @plurals.insert(0, [rule, replacement])
    end

singular(rule, replacement) click to toggle source

Specifies a new singularization rule and its replacement. The rule can either be a string or a regular expression. The replacement should always be a string that may include references to the matched data from the rule.

    # File lib/active_support/inflector/inflections.rb, line 90
    def singular(rule, replacement)
      @uncountables.delete(rule) if rule.is_a?(String)
      @uncountables.delete(replacement)
      @singulars.insert(0, [rule, replacement])
    end

uncountable(*words) click to toggle source

Add uncountable words that shouldn’t be attempted inflected.

Examples:

    uncountable "money"
    uncountable "money", "information"
    uncountable %w( money information rice )

    # File lib/active_support/inflector/inflections.rb, line 125
    def uncountable(*words)
      (@uncountables << words).flatten!
    end