tasks a-s

Task/Permutations/Ursala/permutations-1.ursala

@@ -0,0 +1,9 @@
+#import std
+
+permutations =
+
+~&itB^?a(                     # are both the input argument list and its tail non-empty?
+   @ahPfatPRD *= refer ^C(      # yes, recursively generate all permutations of the tail, and for each one
+      ~&a,                        # insert the head at the first position
+      ~&ar&& ~&arh2falrtPXPRD),   # if the rest is non-empty, recursively insert at all subsequent positions
+   ~&aNC)                       # no, return the singleton list of the argument

Task/Permutations/Ursala/permutations-2.ursala

@@ -0,0 +1,3 @@
+#cast %nLL
+
+test = permutations <1,2,3>