37 lines
859 B
Ruby
37 lines
859 B
Ruby
#
|
||
# shuffle.rb
|
||
#
|
||
|
||
# TODO(Krzysztof Wilczynski): Support for strings would be nice too ...
|
||
|
||
module Puppet::Parser::Functions
|
||
newfunction(:shuffle, :type => :rvalue, :doc => <<-EOS
|
||
EOS
|
||
) do |arguments|
|
||
|
||
raise(Puppet::ParseError, "shuffle(): Wrong number of arguments " +
|
||
"given (#{arguments.size} for 1)") if arguments.size < 1
|
||
|
||
array = arguments[0]
|
||
|
||
if not array.is_a?(Array)
|
||
raise(Puppet::ParseError, 'shuffle(): Requires an array to work with')
|
||
end
|
||
|
||
result = array.clone
|
||
elements = result.size
|
||
|
||
return [] if result.size == 0
|
||
return result if result.size <= 1
|
||
|
||
# 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
|
||
|
||
return result
|
||
end
|
||
end
|
||
|
||
# vim: set ts=2 sw=2 et :
|