(#8709) Add hash merging function

In Puppet, it is not possible to reassign hash
values.

This function allows a reasonable way to perform
hash munging in Puppet.

Reviewed-by: Jeff McCune

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/merge.rb b/lib/puppet/parser/functions/merge.rb
new file mode 100644
index 0000000..6693884
--- /dev/null
+++ b/lib/puppet/parser/functions/merge.rb
@@ -0,0 +1,28 @@
+module Puppet::Parser::Functions
+
+  newfunction(:merge, :type => :rvalue, :doc => <<-'ENDHEREDOC') do |args|
+    Merges two or more hashes together and returns the resulting hash.
+
+    For example:
+
+      $hash1 = {'one' => 1, 'two', => 2}
+      $hash1 = {'two' => 2, 'three', => 2}
+      $merged_hash = merge($hash1, $hash2)
+      # merged_hash =  {'one' => 1, 'two' => 2, 'three' => 2}
+
+    ENDHEREDOC
+
+    if args.length < 2
+      raise Puppet::ParseError, ("merge(): wrong number of arguments (#{args.length}; must be at least 2)")
+    end
+    args.each do |arg|
+      unless arg.is_a?(Hash)
+        raise Puppet::ParseError, "merge: unexpected argument type #{arg.class}, only expects hash arguments"
+      end
+    end
+
+    args.inject({}, :merge)
+
+  end
+
+end