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authorKrzysztof Wilczynski <krzysztof.wilczynski@linux.com>2011-04-26 00:14:38 +0100
committerKrzysztof Wilczynski <krzysztof.wilczynski@linux.com>2011-04-26 00:14:38 +0100
commit45b5b472a119f86919481f9637488bcada02cc75 (patch)
tree88b0b7227886c63a7f5e2ac195bcd6cc31eec0e1
parent4d6b350509ee84a9bd457c2eb0fa4d599f810bf5 (diff)
downloadpuppet-stdlib-45b5b472a119f86919481f9637488bcada02cc75.tar.gz
puppet-stdlib-45b5b472a119f86919481f9637488bcada02cc75.tar.bz2
First version. Simple shuffle function to use within Puppet DSL.
Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
-rw-r--r--shuffle.rb35
1 files changed, 35 insertions, 0 deletions
diff --git a/shuffle.rb b/shuffle.rb
new file mode 100644
index 0000000..d92a3cd
--- /dev/null
+++ b/shuffle.rb
@@ -0,0 +1,35 @@
+#
+# 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
+
+ array = arguments[0]
+
+ if not array.is_a?(Array)
+ raise(Puppet::ParseError, 'shuffle(): Requires an array to work with')
+ end
+
+ return [] if array.size == 0
+ return array if array.size <= 1
+
+ list = array.clone
+ elements = list.size
+
+ # Simple implementation of Fisher–Yates in-place shuffle ...
+ elements.times do |i|
+ j = rand(elements - i) + i
+ list[j], list[i] = list[i], list[j]
+ end
+
+ return list
+ end
+end
+
+# vim: set ts=2 sw=2 et :