# encoding: UTF-8
#
# Copyright (c) 2010-2015 GoodData Corporation. All rights reserved.
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.

module Enumerable
  def mapcat(initial = [], &block)
    reduce(initial) do |a, e|
      block.call(e).each do |x|
        a << x
      end
      a
    end
  end

  def pmapcat(initial = [], &block)
    intermediate = pmap(&block)
    intermediate.reduce(initial) do |a, e|
      e.each do |x|
        a << x
      end
      a
    end
  end

  def pselect(&block)
    intermediate = pmap(&block)
    zip(intermediate).select { |x| x[1] }.map(&:first)
  end

  def rjust(n, x)
    Array.new([0, n - length].max, x) + self
  end

  def ljust(n, x)
    dup.fill(x, length...n)
  end
end