September Morn Update

Task/Matrix-transposition/Erlang/matrix-transposition.erl

@@ -0,0 +1,18 @@
+-module(transmatrix).
+-export([trans/1,transL/1]).
+
+% using built-ins hd = head, tl = tail
+
+trans([[]|_]) -> [];
+trans(M) ->
+  [ lists:map(fun hd/1, M) | transpose( lists:map(fun tl/1, M) ) ].
+
+% Purist version
+
+transL( [ [Elem | Rest] | List] ) ->
+    [ [Elem | [H || [H | _] <- List] ] |
+      transL( [Rest |
+                      [ T || [_ | T] <- List ] ]
+       ) ];
+transL([ [] | List] ) -> transL(List);
+transL([]) -> [].