Add clamp function

Clamp keeps value within the range.
Employ of soft() makes the whole thing is independant of order.

1 files changed, 30 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/clamp.rb b/lib/puppet/parser/functions/clamp.rb
new file mode 100644
index 0000000..432c7c1
--- /dev/null
+++ b/lib/puppet/parser/functions/clamp.rb
@@ -0,0 +1,30 @@
+#
+# clamp.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:clamp, :type => :rvalue, :arity => -2, :doc => <<-EOS
+    Clamps value to a range.
+    EOS
+  ) do |args|
+
+    args.flatten!
+
+    raise(Puppet::ParseError, 'clamp(): Wrong number of arguments, ' +
+          'need three to clamp') if args.size != 3
+
+    # check values out
+    args.each do |value|
+      case [value.class]
+        when [String]
+          raise(Puppet::ParseError, "clamp(): Required explicit numeric (#{value}:String)") unless value =~ /^\d+$/
+        when [Hash]
+          raise(Puppet::ParseError, "clamp(): The Hash type is not allowed (#{value})")
+      end
+    end
+
+    # convert to numeric each element
+    # then sort them and get a middle value
+    args.map{ |n| n.to_i }.sort[1]
+  end
+end