- *Type*: rvalue
+difference
+----------
+This function returns the difference between two arrays.
+The returned array is a copy of the original array, removing any items that
+also appear in the second array.
+
+*Examples:*
+
+ difference(["a","b","c"],["b","c","d"])
+
+Would return: ["a"]
+
dirname
-------
Returns the `dirname` of a path.
- *Type*: rvalue
+intersection
+-----------
+This function returns an array an intersection of two.
+
+*Examples:*
+
+ intersection(["a","b","c"],["b","c","d"])
+
+Would return: ["b","c"]
+
is_array
--------
Returns true if the variable passed to this function is an array.
- *Type*: rvalue
+union
+-----
+This function returns a union of two arrays.
+
+*Examples:*
+
+ union(["a","b","c"],["b","c","d"])
+
+Would return: ["a","b","c","d"]
+
+
unique
------
This function will remove duplicates from strings and arrays.
--- /dev/null
+#
+# difference.rb
+#
+
+module Puppet::Parser::Functions
+ newfunction(:difference, :type => :rvalue, :doc => <<-EOS
+This function returns the difference between two arrays.
+The returned array is a copy of the original array, removing any items that
+also appear in the second array.
+
+*Examples:*
+
+ difference(["a","b","c"],["b","c","d"])
+
+Would return: ["a"]
+ EOS
+ ) do |arguments|
+
+ # Two arguments are required
+ raise(Puppet::ParseError, "difference(): Wrong number of arguments " +
+ "given (#{arguments.size} for 2)") if arguments.size != 2
+
+ first = arguments[0]
+ second = arguments[1]
+
+ unless first.is_a?(Array) && second.is_a?(Array)
+ raise(Puppet::ParseError, 'difference(): Requires 2 arrays')
+ end
+
+ result = first - second
+
+ return result
+ end
+end
+
+# vim: set ts=2 sw=2 et :
--- /dev/null
+#
+# intersection.rb
+#
+
+module Puppet::Parser::Functions
+ newfunction(:intersection, :type => :rvalue, :doc => <<-EOS
+This function returns an array an intersection of two.
+
+*Examples:*
+
+ intersection(["a","b","c"],["b","c","d"])
+
+Would return: ["b","c"]
+ EOS
+ ) do |arguments|
+
+ # Two arguments are required
+ raise(Puppet::ParseError, "intersection(): Wrong number of arguments " +
+ "given (#{arguments.size} for 2)") if arguments.size != 2
+
+ first = arguments[0]
+ second = arguments[1]
+
+ unless first.is_a?(Array) && second.is_a?(Array)
+ raise(Puppet::ParseError, 'intersection(): Requires 2 arrays')
+ end
+
+ result = first & second
+
+ return result
+ end
+end
+
+# vim: set ts=2 sw=2 et :
--- /dev/null
+#
+# union.rb
+#
+
+module Puppet::Parser::Functions
+ newfunction(:union, :type => :rvalue, :doc => <<-EOS
+This function returns a union of two arrays.
+
+*Examples:*
+
+ union(["a","b","c"],["b","c","d"])
+
+Would return: ["a","b","c","d"]
+ EOS
+ ) do |arguments|
+
+ # Two arguments are required
+ raise(Puppet::ParseError, "union(): Wrong number of arguments " +
+ "given (#{arguments.size} for 2)") if arguments.size != 2
+
+ first = arguments[0]
+ second = arguments[1]
+
+ unless first.is_a?(Array) && second.is_a?(Array)
+ raise(Puppet::ParseError, 'union(): Requires 2 arrays')
+ end
+
+ result = first | second
+
+ return result
+ end
+end
+
+# vim: set ts=2 sw=2 et :
--- /dev/null
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the difference function" do
+ let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+ it "should exist" do
+ Puppet::Parser::Functions.function("difference").should == "function_difference"
+ end
+
+ it "should raise a ParseError if there are fewer than 2 arguments" do
+ lambda { scope.function_difference([]) }.should( raise_error(Puppet::ParseError) )
+ end
+
+ it "should return the difference between two arrays" do
+ result = scope.function_difference([["a","b","c"],["b","c","d"]])
+ result.should(eq(["a"]))
+ end
+end
--- /dev/null
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the intersection function" do
+ let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+ it "should exist" do
+ Puppet::Parser::Functions.function("intersection").should == "function_intersection"
+ end
+
+ it "should raise a ParseError if there are fewer than 2 arguments" do
+ lambda { scope.function_intersection([]) }.should( raise_error(Puppet::ParseError) )
+ end
+
+ it "should return the intersection of two arrays" do
+ result = scope.function_intersection([["a","b","c"],["b","c","d"]])
+ result.should(eq(["b","c"]))
+ end
+end
--- /dev/null
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the union function" do
+ let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+ it "should exist" do
+ Puppet::Parser::Functions.function("union").should == "function_union"
+ end
+
+ it "should raise a ParseError if there are fewer than 2 arguments" do
+ lambda { scope.function_union([]) }.should( raise_error(Puppet::ParseError) )
+ end
+
+ it "should join two arrays together" do
+ result = scope.function_union([["a","b","c"],["b","c","d"]])
+ result.should(eq(["a","b","c","d"]))
+ end
+end