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authorKen Barber <ken@bob.sh>2011-04-29 09:27:10 +0200
committerKen Barber <ken@bob.sh>2011-04-30 15:59:31 +0200
commit99a93d366f2e1efb977fcc8fe300d3d8357c8214 (patch)
treefab7510323f123c83da6d7c6cae4fe9e3f2f1e27 /lib/puppet/parser/functions/shuffle.rb
parent781a8720577d0cafe2147f3a1b938db7bec31789 (diff)
Convert to module format.
Diffstat (limited to 'lib/puppet/parser/functions/shuffle.rb')
-rw-r--r--lib/puppet/parser/functions/shuffle.rb45
1 files changed, 45 insertions, 0 deletions
diff --git a/lib/puppet/parser/functions/shuffle.rb b/lib/puppet/parser/functions/shuffle.rb
new file mode 100644
index 0000000..73e798c
--- /dev/null
+++ b/lib/puppet/parser/functions/shuffle.rb
@@ -0,0 +1,45 @@
+#
+# shuffle.rb
+#
+
+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
+
+ value = arguments[0]
+ klass = value.class
+
+ unless [Array, String].include?(klass)
+ 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 :