class Array

@overload zip_with(*args, &block)

Zips the input arrays with `self` and invokes block with the elements
of the zipped array.
@param [Array] args One or more arrays
@example With one input array
   a = [1, 2, 3]
   a.zip_with([3, 2, 1]) { |x, y| x + y } # => [4, 4, 4]
@example With multiple input arrays
   a = [1, 2, 3]
   a.zip_with([4, 5, 6], [7, 8, 9]) do |x, y, z|
     (y - x) * z
   end # => [21, 24, 27]
@return [Array]

@overload zip_with(*args, operator)

Zips the input arrays with `self` and reduces the zipped array with
the +:operator+
@param [Array] args One or more arrays
@param [Symbol] operator Operator to reduce the zipped array with
@example With one input array
   a = [1, 2, 3]
   a.zip_with([3, 2, 1], :+) { |x, y| x + y } # => [4, 4, 4]
@example With multiple input arrays
   a = [1, 2, 3]
   a.zip_with([4, 5, 6], [7, 8, 9], :+) # => [12, 15, 18]
@return [Array]

@raise [ArgumentError] If there is no symbol or a block as the last

parameter.

# File lib/array_zip_with/core_ext/array.rb, line 30
def zip_with(*args)
  return zip(*args).map(&Proc.new) if block_given?
  operator = args.pop
  raise ArgumentError, "A block or symbol \
      must be provided" unless operator.is_a?(Symbol)
  zip(*args).map { |elems| elems.reduce(operator) }
end