diff options
Diffstat (limited to 'puppet/modules/stdlib/lib/puppet/parser/functions/shuffle.rb')
-rw-r--r-- | puppet/modules/stdlib/lib/puppet/parser/functions/shuffle.rb | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/puppet/modules/stdlib/lib/puppet/parser/functions/shuffle.rb b/puppet/modules/stdlib/lib/puppet/parser/functions/shuffle.rb new file mode 100644 index 00000000..30c663db --- /dev/null +++ b/puppet/modules/stdlib/lib/puppet/parser/functions/shuffle.rb @@ -0,0 +1,45 @@ +# +# shuffle.rb +# + +module Puppet::Parser::Functions + newfunction(:shuffle, :type => :rvalue, :doc => <<-EOS +Randomizes the order of a string or array elements. + EOS + ) do |arguments| + + raise(Puppet::ParseError, "shuffle(): Wrong number of arguments " + + "given (#{arguments.size} for 1)") if arguments.size < 1 + + 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 +end + +# vim: set ts=2 sw=2 et : |