Add delimiter substitution for slugs.

lib/slugtastic.rb

@@ -3,8 +3,12 @@ require "slugtastic/model_additions"
 require "slugtastic/railtie" if defined? Rails
 
 module Slugtastic
-  def self.generate_slug(string)
+  def self.generate_slug(string, delimiter = nil)
     return if string.nil?
-    string.parameterize
+    slug = string.parameterize
+    if delimiter
+      slug.gsub!("-", delimiter)
+    end
+    slug
   end
 end

lib/slugtastic/version.rb

@@ -1,3 +1,3 @@
 module Slugtastic
-  VERSION = "1.1.0"
+  VERSION = "1.2.0-alpha"
 end

spec/slugtastic_spec.rb

@@ -11,6 +11,10 @@ describe Slugtastic do
       Slugtastic.generate_slug("A simple string.").should eq "a-simple-string"
     end
 
+    it "substitutes hyphens for delimiter if specified" do
+      Slugtastic.generate_slug("A simple string.", "_").should eq "a_simple_string"
+    end
+
     it "generates a slug from a string with numbers" do
       Slugtastic.generate_slug("Slugtastic was built in 2012.").should eq "slugtastic-was-built-in-2012"
     end