nix/tests/functional/lang/eval-okay-partition.nix

with import ./lib.nix;

builtins.partition
  (x: x / 2 * 2 == x)
  (builtins.concatLists [ (range 0 10) (range 100 110) ])
Add builtin function "partition" The implementation of "partition" in Nixpkgs is O(n^2) (because of the use of ++), and for some reason was causing stack overflows in multi-threaded evaluation (not sure why). This reduces "nix-env -qa --drv-path" runtime by 0.197s and memory usage by 298 MiB (in non-Boehm mode). 2016-08-29 15:28:20 +00:00			`with import ./lib.nix;`

			`builtins.partition`
			`(x: x / 2 * 2 == x)`
			`(builtins.concatLists [ (range 0 10) (range 100 110) ])`