Module: Pluralizr

Included in:
String
Defined in:
lib/pluralizr.rb,
lib/pluralizr/lists.rb,
lib/pluralizr/rules.rb,
lib/pluralizr/version.rb,
lib/pluralizr/exceptions.rb

Overview

A module that takes a single word and returns the pluralized version of that word. It attempts to take into account various rules—like, handling words that end in ‘y’ where the ‘y’ is preceded by a vowel or consonant (i.e., day -> days versus baby -> babies)—as well as words of French, Greek and Latin origins.

Defined Under Namespace

Classes: InvalidStringError, InvalidTypeError, TooManyWordsError

Constant Summary collapse

EXCEPTIONS_LIST =

List of words that are exceptions to the rules in the RULES constant variable hash.

{
  # SXZCHSH_EXCEPTIONS
  'quiz'          =>    'quizzes',
  'stomach'       =>    'stomachs',
  'epoch'         =>    'epochs',

  # FE_F_EXCEPTIONS
  'chef'          =>    'chefs',
  'dwarf'         =>    'dwarfs',
  'gulf'          =>    'gulfs',
  'hoof'          =>    'hooves',
  'safe'          =>    'safes',
  'surf'          =>    'surfs',
  'turf'          =>    'turfs',

  # EX_EXCEPTIONS
  'annex'         =>    'annexes',
  'complex'       =>    'complexes',
  'duplex'        =>    'duplexes',
  'hex'           =>    'hexes',
  'index'         =>    'indexes',
  'sex'           =>    'sexes',

  # O_EXCEPTIONS
  'albino'        =>    'albinos',
  'armadillo'     =>    'armadillos',
  'auto'          =>    'autos',
  'cello'         =>    'cellos',
  'combo'         =>    'combos',
  'ego'           =>    'egos',
  'halo'          =>    'halos',
  'inferno'       =>    'infernos',
  'lasso'         =>    'lassos',
  'memento'       =>    'mementos',
  'memo'          =>    'memos',
  'piano'         =>    'pianos',
  'photo'         =>    'photos',
  'pro'           =>    'pros',
  'silo'          =>    'silos',
  'solo'          =>    'solos',
  'taco'          =>    'tacos',
  'tuxedo'        =>    'tuxedos',
  'typo'          =>    'typos',

  # UM_EXCEPTIONS
  'album'         =>    'albums',
  'stadium'       =>    'stadiums',
  'minimum'       =>    'minimums',
  'maximum'       =>    'maximums',
  'premium'       =>    'premiums',
  'vacuum'        =>    'vacuums',

  # STRICT_LATIN_ORIGINS
  'radius'        =>    'radii',
  'alumnus'       =>    'alumni',
  'cactus'        =>    'cacti',
  'fungus'        =>    'fungi',
  'nucleus'       =>    'nuclei',
  'genus'         =>    'genera',
  'syllabus'      =>    'syllabi',
  'alga'          =>    'algae',
  'vertebra'      =>    'vertebrae',
  'larva'         =>    'larvae',

  # STRICT_GREEK_ORIGINS
  'automaton'     =>    'automata',
  'criterion'     =>    'criteria',
  'phenomenon'    =>    'phenomena',

  # ITALIAN_ORIGINS
  'espresso'      =>    'espressos',
  'pizza'         =>    'pizzas',
  'risotto'       =>    'risottos',
  'paparazzo'       =>    'paparazzi',
  'spaghetto'       =>    'spaghetti'
}
IRREGULAR_WORDS =

List of words whose plural form doesn’t adhere to a rule in the RULES hash, but instead, often mutates the original word. For example, mouse => mice. Or, foot => feet.

{
  'child'         =>    'children',
  'die'           =>    'dice',
  'foot'          =>    'feet',
  'goose'         =>    'geese',
  'louse'         =>    'lice',
  'man'           =>    'men',
  'mouse'         =>    'mice',
  'ox'            =>    'oxen',
  'person'        =>    'people',
  'that'          =>    'those',
  'this'          =>    'these',
  'tooth'         =>    'teeth',
  'woman'         =>    'women'
}
SINGULAR_AND_PLURAL_FORMS_ARE_THE_SAME =

List of words whose plural form is the same as its singular form. For example, deer is used in both singular and plural contexts.

%w(advice aircraft bison corn deer equipment evidence gold information jewelry kin legislation luck luggage moose music offspring sheep silver swine trousers trout wheat)
PLURAL_ONLY_WORDS =

List of words that only have a plural form. There is no singular form of the word. For example, the word tweezers has no singular form. The word tweezer is actually a verb and not a noun.

%w(barracks bellows cattle deer dregs eyeglasses gallows headquarters mathematics means measles mumps news oats pants pliers pajamas scissors series shears shorts species tongs tweezers vespers)
RULES =

Hash containing the various rules for specific word endings in the English language. – These endings are stored in the hash as keys. Each key has a set of properties as its value. These properties specify the word’s plural form ending, how the plural form should be applied to the original word, and if there are any words considered exceptions to the particular rule.

For example, given a word that ends in ‘a’, the pluralize() method will check for errors (see exceptions.rb) and special cases (see lists.rb), and then iterate through the RULES hash below. Since the word ends in ‘a’, it matches with the RULES key, and since this list contains an exceptions list, it checks if the word is on the list. If so, it returns the plural version of that word from the exceptions list. If not, it adds an ‘s’ to the end of the original word and returns it.

{
  'ia'        =>  { with_ending: 's',    offset: -1 },
  'a'         =>  { with_ending: 's',    offset: -1, has_exception_list: true },
  'ffe'       =>  { with_ending: 's',    offset: -1 },
  'fe'        =>  { with_ending: 'ves',  offset: -3, has_exception_list: true },
  'ff'        =>  { with_ending: 's',    offset: -1 },
  'f'         =>  { with_ending: 'ves',  offset: -2, has_exception_list: true },
  'ch'        =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  'sh'        =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  'um'        =>  { with_ending: 'a',    offset: -3, has_exception_list: true },
  'tion'      =>  { with_ending: 's',    offset: -1 },
  'on'        =>  { with_ending: 's',    offset: -1, has_exception_list: true },
  'o'         =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  'is'        =>  { with_ending: 'es',   offset: -3 },
  'us'        =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  's'         =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  'eau'       =>  { with_ending: 's',    offset: -1 },
  'ex'        =>  { with_ending: 'ices', offset: -3, has_exception_list: true },
  'x'         =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  'y'         =>  { with_ending: 'ies',  offset: -2 },
  'z'         =>  { with_ending: 'es',   offset: -1, has_exception_list: true },
  'irregular' =>  {                      offset: -1, has_exception_list: true },
  'default'   =>  { with_ending: 's',    offset: -1 }
}
VERSION =

Current gem version.

"0.2.0"

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.pluralize(word) ⇒ Object

Pluralizes the object passed in or returns an error if an exception is raised.

Parameters:

word

The object passed in.

Returns:

Either an error message, if any exceptions are raised via Pluralizr.check_for_errors method, or the appropriate plural version of the word passed into the method.



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# File 'lib/pluralizr.rb', line 25

def self.pluralize(word)

  check_for_errors(word)

  case
  when word.is_irregular? then return IRREGULAR_WORDS[word]
  when word.has_same_singular_and_plural_form? || word.only_has_plural_form?
    return word
  when word.ends_with_vowel_and_y_or_o? || word.ends_with_double_vowel_and_f?
    return word.insert(-1, 's')
  else
    RULES.each do |rule, props| 
      return find_plural_of(word, props) if word.end_with?(rule)
    end
  end
  return find_plural_of(word, RULES['default'])
end

Instance Method Details

#ends_with_double_vowel_and_f? ⇒ Boolean

Returns true if the word (the caller) ends in a double vowel plus ‘f’. For example, proof or handkerchief.

Returns:

  • (Boolean) 


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# File 'lib/pluralizr.rb', line 54

def ends_with_double_vowel_and_f?
  self.match(/[aeiouy]+[f]$/i)
end

#ends_with_vowel_and_y_or_o? ⇒ Boolean

Returns true if the word (the caller) ends in a vowel plus either a ‘y’ or an ‘o’. For example, day and valley or stereo and tattoo.

Returns:

  • (Boolean) 


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# File 'lib/pluralizr.rb', line 47

def ends_with_vowel_and_y_or_o?
  self.match(/[aeiouy][oy]$/i)
end

#has_same_singular_and_plural_form? ⇒ Boolean

Returns true if the word (the caller) is found in the SINGULAR_AND_PLURAL_FORMS_ARE_THE_SAME hash.

Returns:

  • (Boolean) 


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# File 'lib/pluralizr.rb', line 75

def has_same_singular_and_plural_form?
  SINGULAR_AND_PLURAL_FORMS_ARE_THE_SAME.include?(self)
end

#is_irregular? ⇒ Boolean

Returns true if the word (the caller) is found in the IRREGULAR_WORDS hash.

Returns:

  • (Boolean) 


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# File 'lib/pluralizr.rb', line 61

def is_irregular?
  IRREGULAR_WORDS.include?(self)
end

#only_has_plural_form? ⇒ Boolean

Returns true if the word (the caller) is found in the PLURAL_ONLY_WORDS hash.

Returns:

  • (Boolean) 


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# File 'lib/pluralizr.rb', line 68

def only_has_plural_form?
  PLURAL_ONLY_WORDS.include?(self)
end