Merge pull request #239722 from Stunkymonkey/lib-allUnique

lib.lists.allUnique: init
NixOS · Nov 15, 2023 · b04b7d6 · b04b7d6
2 parents 486911d + 66261e9
commit b04b7d6
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Showing 3 changed files with 23 additions and 1 deletion.
diff --git a/lib/default.nix b/lib/default.nix
@@ -92,7 +92,7 @@ let
       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

diff --git a/lib/lists.nix b/lib/lists.nix
@@ -821,6 +821,19 @@ rec {
    */
   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:

diff --git a/lib/tests/misc.nix b/lib/tests/misc.nix
@@ -726,6 +726,15 @@ runTests {
     expected = 7;
   };
 
+  testAllUnique_true = {
+    expr = allUnique [ 3 2 4 1 ];
+    expected = true;
+  };
+  testAllUnique_false = {
+    expr = allUnique [ 3 2 3 4 ];
+    expected = false;
+  };
+
 # ATTRSETS
 
   testConcatMapAttrs = {