Ruby core extension for Array#find_value which compares each entry in enum with value or passes to block and returns the value for the first for which the evaluated value is non-false.

find_value.rb

class Array
  # Compares each entry in enum with value or passes to block. Returns the value
  # for the first for which the evaluated value is non-false. If no object
  # matches, returns the default value or nil.
  #
  # If neither block nor argument is given, an enumerator is returned instead.
  #
  #  find_value(value, default = nil) → obj or default
  #  find_value(default = nil) { |obj| block } → obj or default
  #  find_value → an_enumerator
  def find_value(*args, &block)
    return find_index if args.empty? unless block_given?

    if block_given?
      fail ArgumentError, "wrong number of arguments (#{args.size} for 0..1)" unless (0..1).include? args.size
      default = args.pop
      index = find_index &block
    else
      fail ArgumentError, "wrong number of arguments (#{args.size} for 1..2)" unless (1..2).include? args.size
      default = args.size == 2 ? args.pop : nil
      index = find_index args.pop
    end

    return default unless index
    fetch index
  end
end