1 files changed, 45 insertions, 0 deletions
diff --git a/puppet/modules/stdlib/lib/puppet/parser/functions/prefix.rb b/puppet/modules/stdlib/lib/puppet/parser/functions/prefix.rb
new file mode 100644
index 00000000..d02286af
--- /dev/null
+++ b/puppet/modules/stdlib/lib/puppet/parser/functions/prefix.rb
@@ -0,0 +1,45 @@
+#
+# prefix.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:prefix, :type => :rvalue, :doc => <<-EOS
+This function applies a prefix to all elements in an array.
+
+*Examples:*
+
+    prefix(['a','b','c'], 'p')
+
+Will return: ['pa','pb','pc']
+    EOS
+  ) do |arguments|
+
+    # Technically we support two arguments but only first is mandatory ...
+    raise(Puppet::ParseError, "prefix(): Wrong number of arguments " +
+      "given (#{arguments.size} for 1)") if arguments.size < 1
+
+    array = arguments[0]
+
+    unless array.is_a?(Array)
+      raise Puppet::ParseError, "prefix(): expected first argument to be an Array, got #{array.inspect}"
+    end
+
+    prefix = arguments[1] if arguments[1]
+
+    if prefix
+      unless prefix.is_a?(String)
+        raise Puppet::ParseError, "prefix(): expected second argument to be a String, got #{prefix.inspect}"
+      end
+    end
+
+    # Turn everything into string same as join would do ...
+    result = array.collect do |i|
+      i = i.to_s
+      prefix ? prefix + i : i
+    end
+
+    return result
+  end
+end
+
+# vim: set ts=2 sw=2 et :