Merge pull request #239722 from Stunkymonkey/lib-allUnique

lib.lists.allUnique: init

lib/default.nix

···
       concatMap flatten remove findSingle findFirst any all count
       optional optionals toList range replicate partition zipListsWith zipLists
       reverseList listDfs toposort sort naturalSort compareLists take
-      drop sublist last init crossLists unique intersectLists
+      drop sublist last init crossLists unique allUnique intersectLists
       subtractLists mutuallyExclusive groupBy groupBy';
     inherit (self.strings) concatStrings concatMapStrings concatImapStrings
       intersperse concatStringsSep concatMapStringsSep

lib/lists.nix

···
    */
   unique = foldl' (acc: e: if elem e acc then acc else acc ++ [ e ]) [];
 
+  /* Check if list contains only unique elements. O(n^2) complexity.
+
+     Type: allUnique :: [a] -> bool
+
+     Example:
+       allUnique [ 3 2 3 4 ]
+       => false
+       allUnique [ 3 2 4 1 ]
+       => true
+   */
+  allUnique = list: (length (unique list) == length list);
+
+
   /* Intersects list 'e' and another list. O(nm) complexity.
 
      Example:

lib/tests/misc.nix

···
     expected = 7;
   };
 
+  testAllUnique_true = {
+    expr = allUnique [ 3 2 4 1 ];
+    expected = true;
+  };
+  testAllUnique_false = {
+    expr = allUnique [ 3 2 3 4 ];
+    expected = false;
+  };
+
 # ATTRSETS
 
   testConcatMapAttrs = {