Merge pull request #976 from chaokunyang/master

fix out-of-order: def foldLeft[B](z: B)(op: (A,B) => B): B

Author: SethTisue

_style/declarations.md

@@ -207,7 +207,7 @@ There are three main reasons you should do this:
     type inferencer can allow a simpler syntax when invoking the
     remaining parameter lists. Consider fold:
 
-        def foldLeft[B](z: B)(op: (A,B) => B): B
+        def foldLeft[B](z: B)(op: (B, A) => B): B
         List("").foldLeft(0)(_ + _.length)
 
         // If, instead: