(#19201) Add concat function to join two arrays

Without this patch applied there is no easy way to append one array to
another.  This is a problem because it is often desirable to join two
arrays without flattening the contents into a single, one dimensional
array.

This patch addresses the problem by adding a `concat()` function which
takes two arguments.  The arguments will be concatenated together and a
new array returned to the caller.

Reviewed-by: Jeff McCune <jeff@puppetlabs.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/concat.rb b/lib/puppet/parser/functions/concat.rb
new file mode 100644
index 0000000..c86aa00
--- /dev/null
+++ b/lib/puppet/parser/functions/concat.rb
@@ -0,0 +1,37 @@
+#
+# concat.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:concat, :type => :rvalue, :doc => <<-EOS
+Appends the contents of array 2 onto array 1.
+
+*Example:*
+
+    concat(['1','2','3'],['4','5','6'])
+
+Would result in:
+
+  ['1','2','3','4','5','6']
+    EOS
+  ) do |arguments|
+
+    # Check that 2 arguments have been given ...
+    raise(Puppet::ParseError, "concat(): Wrong number of arguments " +
+      "given (#{arguments.size} for 2)") if arguments.size != 2
+
+    a = arguments[0]
+    b = arguments[1]
+
+    # Check that both args are arrays.
+    unless a.is_a?(Array) and b.is_a?(Array)
+      raise(Puppet::ParseError, 'concat(): Requires array to work with')
+    end
+
+    result = a.concat(b)
+
+    return result
+  end
+end
+
+# vim: set ts=2 sw=2 et :