Add sortWith

libraries/List.elm

@@ -22,7 +22,7 @@ list must have the same type.
 @docs sum, product, maximum, minimum, all, any, and, or
 
 # Sorting
-@docs sort, sortBy
+@docs sort, sortBy, sortWith
 -}
 
 import open Basics
@@ -232,6 +232,11 @@ repeat = Native.List.repeat
 sort : [comparable] -> [comparable]
 sort = Native.List.sort
 
-{-| Sort a list by a given comparison function. -}
+{-| Sort a list by a given comparison transformation, such a [record field
+accessors](http://elm-lang.org/learn/Syntax.elm#records). -}
 sortBy : (a -> comparable) ->  [a] -> [a]
 sortBy = Native.List.sortBy
+
+{-| Sort a list by a given comparison function. -}
+sortWith : (a -> a -> Order) ->  [a] -> [a]
+sortWith = Native.List.sortWith

libraries/Native/List.js

@@ -222,6 +222,13 @@ Elm.Native.List.make = function(elm) {
         }));
     }
 
+    function sortWith(f, xs) {
+        return fromArray(toArray(xs).sort(function(a,b){
+            var ord = f(a)(b).ctor;
+            return ord === 'EQ' ? 0 : ord === 'LT' ? -1 : 1;
+        }));
+    }
+
     function nth(xs, n) {
         return toArray(xs)[n];
     }
@@ -301,6 +308,7 @@ Elm.Native.List.make = function(elm) {
         zip:F2(zip),
         sort:sort,
         sortBy:F2(sortBy),
+        sortWith:F2(sortWith),
         nth:F2(nth),
         take:F2(take),
         drop:F2(drop),