diff options
| author | Vincent Ambo <mail@tazj.in> | 2022-12-29T11·44+0300 |
|---|---|---|
| committer | tazjin <tazjin@tvl.su> | 2022-12-29T12·27+0000 |
| commit | 5d73c06b1a67bce68dcc0b2bd5f087ce00ab6317 (patch) | |
| tree | 62d40c8ca8e1620bff028c8d89a5a0f05ee00661 /tvix/eval/src/vm.rs | |
| parent | 6ab8320f075e36f2328a86f5fcf7674844a0bd12 (diff) | |
refactor(tvix/eval): use im::Vector for NixList representation r/5534
This is a persistent, structurally sharing data structure which is more efficient in some of our use-cases. I have verified the efficiency improvement using `hyperfine` repeatedly over expressions on nixpkgs. Lists are not the most performance-critical structure in Nix (that would be attribute sets), but we can already see a small (~5-10%) improvement. Note that there are a handful of cases where we still go via `Vec` that need to be fixed, most notable for `builtins.sort` which can not currently be implemented directly using `im::Vector` because of a restrictive type bound. Change-Id: I237cc50cbd7629a046e5a5e4601fbb40355e551d Reviewed-on: https://cl.tvl.fyi/c/depot/+/7670 Tested-by: BuildkiteCI Reviewed-by: sterni <sternenseemann@systemli.org>
Diffstat (limited to 'tvix/eval/src/vm.rs')
| -rw-r--r-- | tvix/eval/src/vm.rs | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs index f1dc99439638..5bc0f7736ae4 100644 --- a/tvix/eval/src/vm.rs +++ b/tvix/eval/src/vm.rs @@ -815,10 +815,9 @@ impl<'o> VM<'o> { } OpCode::OpConcat => { - let rhs = fallible!(self, self.pop().to_list()); - let mut lhs = fallible!(self, self.pop().to_list()).into_vec(); - lhs.extend_from_slice(&rhs); - self.push(Value::List(NixList::from(lhs))) + let rhs = fallible!(self, self.pop().to_list()).into_inner(); + let lhs = fallible!(self, self.pop().to_list()).into_inner(); + self.push(Value::List(NixList::from(lhs + rhs))) } OpCode::OpInterpolate(Count(count)) => self.run_interpolate(count)?, |