Array#index to take block; fix #2968 close #2970

1 files changed, 28 insertions, 0 deletions

diff --git a/mrbgems/mruby-array-ext/mrblib/array.rb b/mrbgems/mruby-array-ext/mrblib/array.rb
index 1f1d97376..35be79339 100644
--- a/mrbgems/mruby-array-ext/mrblib/array.rb
+++ b/mrbgems/mruby-array-ext/mrblib/array.rb
@@ -681,4 +681,32 @@ class Array
     return nil if self.size == result.size
     self.replace(result)
   end
+
+  ##
+  #  call-seq:
+  #     ary.index(val)            -> int or nil
+  #     ary.index {|item| block } ->  int or nil
+  #
+  #  Returns the _index_ of the first object in +ary+ such that the object is
+  #  <code>==</code> to +obj+.
+  #
+  #  If a block is given instead of an argument, returns the _index_ of the
+  #  first object for which the block returns +true+.  Returns +nil+ if no
+  #  match is found.
+  #
+  # ISO 15.2.12.5.14
+  def index(val=NONE, &block)
+    return to_enum(:find_index, val) if !block && val == NONE
+
+    if block
+      idx = 0
+      self.each do |*e|
+        return idx if block.call(*e)
+        idx += 1
+      end
+    else
+      return self.__ary_index(val)
+    end
+    nil
+  end
 end