add a "step" argument to range()

This patch adds an optional "step" argument to the stdlib range()
function.  There is no change to the default behavior of the function;
however, passing a numeric "step" argument invokes the Ruby Range#step
method, e.g.

    range("0", "9", "2")

returns

    [0,2,4,6,8]

1 files changed, 30 insertions, 0 deletions

diff --git a/spec/unit/puppet/parser/functions/range_spec.rb b/spec/unit/puppet/parser/functions/range_spec.rb
index 8c2446a..24cc391 100644
--- a/spec/unit/puppet/parser/functions/range_spec.rb
+++ b/spec/unit/puppet/parser/functions/range_spec.rb
@@ -23,9 +23,39 @@ describe "the range function" do
     result.should(eq(['a','b','c','d']))
   end
 
+  it "should return a letter range given a step of 1" do
+    result = @scope.function_range(["a","d","1"])
+    result.should(eq(['a','b','c','d']))
+  end
+
+  it "should return a stepped letter range" do
+    result = @scope.function_range(["a","d","2"])
+    result.should(eq(['a','c']))
+  end
+
+  it "should return a stepped letter range given a negative step" do
+    result = @scope.function_range(["1","4","-2"])
+    result.should(eq(['a','c']))
+  end
+
   it "should return a number range" do
     result = @scope.function_range(["1","4"])
     result.should(eq([1,2,3,4]))
   end
 
+  it "should return a number range given a step of 1" do
+    result = @scope.function_range(["1","4","1"])
+    result.should(eq([1,2,3,4]))
+  end
+
+  it "should return a stepped number range" do
+    result = @scope.function_range(["1","4","2"])
+    result.should(eq([1,3]))
+  end
+
+  it "should return a stepped number range given a negative step" do
+    result = @scope.function_range(["1","4","-2"])
+    result.should(eq([1,3]))
+  end
+
 end