class Dry::Inflector::Inflections

def self.build(&blk)
  new do |inflect|
    Defaults.call(inflect)
    blk.call(inflect) if block_given?
  end
end

def acronym(*words)
  words.each { |word| @acronyms.add(word.downcase, word) }
end

def add_irregular(rule, replacement, target)
  head, *tail = rule.chars.to_a
  rule(/(#{head})#{tail.join}\z/i, "\\1#{replacement[1..]}", target)
end

def human(rule, replacement)
  humans.insert(0, [rule, replacement])
end

def initialize
  @plurals      = Rules.new
  @singulars    = Rules.new
  @humans       = Rules.new
  @uncountables = Set[]
  @acronyms     = Acronyms.new
  yield(self) if block_given?
end

def irregular(singular, plural)
  uncountables.delete(singular)
  uncountables.delete(plural)
  add_irregular(singular, plural, plurals)
  add_irregular(plural, singular, singulars)
end

def plural(rule, replacement)
  rule(rule, replacement, plurals)
end

def rule(rule, replacement, target)
  uncountables.delete(rule)
  uncountables.delete(replacement)
  target.insert(0, [rule, replacement])
end

def singular(rule, replacement)
  rule(rule, replacement, singulars)
end

def uncountable(*words)
  uncountables.merge(words.flatten)
end