Puppet Function: shuffle

Defined in:
lib/puppet/parser/functions/shuffle.rb
Function type:
Ruby 3.x API

Overview

shuffle() ⇒ Any

Randomizes the order of a string or array elements.

Returns:

  • (Any) 


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# File 'lib/puppet/parser/functions/shuffle.rb', line 5

newfunction(:shuffle, :type => :rvalue, :doc => <<-DOC
  Randomizes the order of a string or array elements.
DOC
           ) do |arguments|

  raise(Puppet::ParseError, "shuffle(): Wrong number of arguments given (#{arguments.size} for 1)") if arguments.empty?

  value = arguments[0]

  unless value.is_a?(Array) || value.is_a?(String)
    raise(Puppet::ParseError, 'shuffle(): Requires either array or string to work with')
  end

  result = value.clone

  string = value.is_a?(String) ? true : false

  # Check whether it makes sense to shuffle ...
  return result if result.size <= 1

  # We turn any string value into an array to be able to shuffle ...
  result = string ? result.split('') : result

  elements = result.size

  # Simple implementation of Fisher–Yates in-place shuffle ...
  elements.times do |i|
    j = rand(elements - i) + i
    result[j], result[i] = result[i], result[j]
  end

  result = string ? result.join : result

  return result
end