Merge remote-tracking branch 'upstream/master' into mrbgems

1 files changed, 15 insertions, 4 deletions

diff --git a/mrblib/enum.rb b/mrblib/enum.rb
index 2699a18af..2774bc856 100644
--- a/mrblib/enum.rb
+++ b/mrblib/enum.rb
@@ -200,19 +200,30 @@ module Enumerable
   # ISO 15.3.2.2.11
   def inject(*args, &block)
     raise ArgumentError, "too many arguments" if args.size > 2
-    flag = true  # 1st element?
-    result = nil
+    if Symbol === args[-1]
+      sym = args[-1]
+      block = ->(x,y){x.send(sym,y)}
+      args.pop
+    end
+    if args.empty?
+      flag = true  # no initial argument
+      result = nil
+    else
+      flag = false
+      result = args[0]
+    end
     self.each{|val|
       if flag
-        # 1st element
-        result = (args.empty?)? val: block.call(args[0], val)
+        # push first element as initial
         flag = false
+        result = val
       else
         result = block.call(result, val)
       end
     }
     result
   end
+  alias reduce inject
 
   ##
   # Alias for collect