Add optional block to allow sorting of arrays of arbitrary objects

Author: ikbenale

README.md

@@ -15,6 +15,12 @@ VersionSorter.sort(versions)
 #=> 2.0
 ```
 
+You can also sort arrays of arbitrary objects by providing a block.
+
+```rb
+VersionSorter.sort(tags) { |tag| tag.name }
+```
+
 Library API:
 
 ```rb

ext/version_sorter/version_sorter.c

@@ -185,8 +185,15 @@ rb_version_sort_1(VALUE rb_self, VALUE rb_version_array, compare_callback_t cmp)
 	versions = xcalloc(length, sizeof(struct version_number *));
 
 	for (i = 0; i < length; ++i) {
-		VALUE rb_version = rb_ary_entry(rb_version_array, i);
-		versions[i] = parse_version_number(StringValuePtr(rb_version));
+		VALUE rb_version, rb_version_string;
+
+		rb_version = rb_ary_entry(rb_version_array, i);
+		if (rb_block_given_p())
+			rb_version_string = rb_yield(rb_version);
+		else
+			rb_version_string = rb_version;
+
+		versions[i] = parse_version_number(StringValuePtr(rb_version_string));
 		versions[i]->rb_version = rb_version;
 	}
 

test/version_sorter_test.rb

@@ -4,6 +4,14 @@
 require 'rubygems/version'
 
 class VersionSorterTest < Test::Unit::TestCase
+  def setup
+    version_struct = Struct.new(:name)
+
+    @version1 = version_struct.new("1.0")
+    @version2 = version_struct.new("2.0")
+    @version10 = version_struct.new("10.0")
+  end
+
   def test_sorts_versions_correctly
     versions = %w(1.0.9 1.0.10 2.0 3.1.4.2 1.0.9a)
     sorted_versions = %w( 1.0.9a 1.0.9 1.0.10 2.0 3.1.4.2 )
@@ -71,6 +79,18 @@ def test_rsort_bang
     assert_equal ["10.0", "2.0", "1.0"], versions
   end
 
+  def test_sort_block
+    versions = [@version10, @version1, @version2]
+    sorted = VersionSorter.sort(versions) { |version| version.name }
+    assert_equal [@version1, @version2, @version10], sorted
+  end
+
+  def test_rsort_block
+    versions = [@version10, @version1, @version2]
+    sorted = VersionSorter.rsort(versions) { |version| version.name }
+    assert_equal [@version10, @version2, @version1], sorted
+  end
+
   def shuffle(array)
     array, result = array.dup, []
     result << array.delete_at(rand(array.size)) until array.size.zero?