maj list

HerrmannM
1 parent 6730102e
Showing 1 changed file with 12 additions and 2 deletions Show diff stats
anubis_dev/library/tools/list.anubis
@@ -825,7 +825,7 @@ public define List($A) unfold($B item, $B -&gt; Result($A, ($A, $B)) unspool) = if 
   *** Zip
       ==================================================================================================================
-define Maybe(List(($T,$T))) zip(List($T) lg, List($T) ld, List(($T,$T)) acc) =
+define Maybe(List(($T1, $T2))) zip(List($T1) lg, List($T2) ld, List(($T1, $T2)) acc) =
   if lg is
   {
     [ ] then if ld is [ ] then success(reverse(acc)) else failure,
@@ -835,7 +835,17 @@ define Maybe(List(($T,$T))) zip(List($T) lg, List($T) ld, List(($T,$T)) acc) =
   }.
     Zip two lists into a list of tuples. Returns failure if the two lists have different length.
-public define Maybe(List(($T,$T))) zip(List($T) lg, List($T) ld) = zip(lg, ld, []).
+public define Maybe(List(($T1,$T2))) zip(List($T1) lg, List($T2) ld) = zip(lg, ld, []).
+
+    Note: The list is pre-reversed in the public interface.
+define (List($T1), List($T2)) unzip(List(($T1, $T2)) list, List($T1) accl, List($T2) accr) =
+  if list is
+  {
+    [ ] then (accl, accr),
+    [h . t] then unzip(t, [p1(h) . accl], [p2(h) . accr])
+  }.
+
+public define (List($T1), List($T2)) unzip(List(($T1, $T2)) l) = unzip(reverse(l), [], []).