* lib/prime.rb: Have with_index accept an offset parameter.

  Based on patch by T Yamada. [#11007]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50854 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 9 insertions, 1 deletions

diff --git a/lib/prime.rb b/lib/prime.rb
index d361e96720..757538db79 100644
--- a/lib/prime.rb
+++ b/lib/prime.rb
@@ -269,7 +269,15 @@ class Prime
     end
 
     # see +Enumerator+#with_index.
-    alias with_index each_with_index
+    def with_index(offset = 0)
+      return enum_for(:with_index, offset) unless block_given?
+      return each_with_index(&proc) if offset == 0
+
+      each do |prime|
+        yield prime, offset
+        offset += 1
+      end
+    end
 
     # see +Enumerator+#with_object.
     def with_object(obj)