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authorEelco Dolstra <eelco.dolstra@logicblox.com>2016-08-29T15·28+0200
committerEelco Dolstra <eelco.dolstra@logicblox.com>2016-08-29T17·36+0200
commit26d92017d3b36cff940dcb7d1611c42232edb81a (patch)
tree856350170478111ea3a61b3b457e4fbee40826ce /tests/lang/eval-okay-partition.nix
parentc0a7b84748d5e27e6804117b8a57ce71269c3c66 (diff)
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).
Diffstat (limited to 'tests/lang/eval-okay-partition.nix')
-rw-r--r--tests/lang/eval-okay-partition.nix5
1 files changed, 5 insertions, 0 deletions
diff --git a/tests/lang/eval-okay-partition.nix b/tests/lang/eval-okay-partition.nix
new file mode 100644
index 000000000000..846d2ce49486
--- /dev/null
+++ b/tests/lang/eval-okay-partition.nix
@@ -0,0 +1,5 @@
+with import ./lib.nix;
+
+builtins.partition
+  (x: x / 2 * 2 == x)
+  (builtins.concatLists [ (range 0 10) (range 100 110) ])