Initial commit

src/genAttrs.nix

@@ -0,0 +1,10 @@
+lib:
+let
+  genAttrsOld = names: f: lib.listToAttrs (map (n: lib.nameValuePair n (f n)) names);
+  genAttrsNew = names: f: lib.listToAttrs (map (n: { name = n; value = f n; }) names);
+
+  bigdata = lib.imap0 (i: _: toString i) (lib.replicate 999999 null);
+in {
+  old = genAttrsOld bigdata (_: null);
+  new = genAttrsNew bigdata (_: null);
+}

src/keepAttrs.nix

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+lib:
+let
+  keepAttrsOld = attrs: names: lib.filterAttrs (n: _: builtins.elem n names) attrs;
+  keepAttrsNew = attrs: names: builtins.intersectAttrs (lib.genAttrs names (_: null)) attrs;
+
+  bigdata = lib.genAttrs (lib.imap0 (i: _: toString i) (lib.replicate 999999 null)) (_: null);
+in {
+  old = keepAttrsOld bigdata [ "123" "456" ];
+  new = keepAttrsNew bigdata [ "123" "456" ];
+}

src/subtractLists.nix

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+lib:
+let
+  # O(nm)
+  subtractListsOld = e: builtins.filter (x: !(builtins.elem x e));
+
+  # O(n + m) (hopefully)
+  subtractListsNew = e: let
+    # Assuming genAttrs is O(n)
+    e' = lib.genAttrs e (_: null);
+  # Assuming hasAttr is O(1)
+  in builtins.filter (x: !(builtins.hasAttr x e'));
+
+  bigdata = lib.imap0 (i: _: toString i) (lib.replicate 999999 null);
+in {
+  old = subtractListsOld [ "123" "456" "789" ] bigdata;
+  new = subtractListsNew [ "123" "456" "789" ] bigdata;
+}

src/unique.nix

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+lib:
+let
+  uniqueOld = builtins.foldl' (acc: e: if builtins.elem e acc then acc else acc ++ [ e ]) [];
+  # uniqueNew = xs: let
+  #   entries = lib.genAttrs xs (_: null);
+  # in builtins.concatMap (x: if );
+
+  bigdataMostlyDuplicates = (lib.replicate 999999 null) ++ ["unique"];
+  bigdataMostlyUnique = lib.imap0 (i: _: toString i) (lib.replicate 999999 null) ++ ["123" "456"];
+in {
+  old = uniqueOld bigdataMostlyDuplicates;
+}