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| author | Adam Joseph <adam@westernsemico.com> | 2022-11-23T08·34-0800 |
|---|---|---|
| committer | clbot <clbot@tvl.fyi> | 2022-11-23T13·02+0000 |
| commit | a740653c83436e3adc14343efa82422eb0a44933 (patch) | |
| tree | 685fd9550b9ac0caf5330f95a801b93de92a3d96 /tvix/eval/src/vm.rs | |
| parent | c537cc6fcee5f5cde4b0e6f8c5d6dcd5d8e3690f (diff) | |
feat(tvix/eval): make NixList::clone() cheap r/5301
When we start unrecursivifying (sp?) things, Rust's borrow checker is going to be a headache; its magic only works when you use the CPU stack as your call stack. Fixing the borrow checker issues usually involves adding lots of `clone()`s. Right now `NixList` is the only variant of `Value` that isn't cheap to clone() -- all the others are either a wrapper around Rc or else are of bounded size. Note that this requires dropping the `DerefMut for NixList` instance and using `Vec<Value>` instead in those situations. Change-Id: I5a47df66855342aa2064f8f3cb7934ff422d26bd Signed-off-by: Adam Joseph <adam@westernsemico.com> Reviewed-on: https://cl.tvl.fyi/c/depot/+/7359 Reviewed-by: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI
Diffstat (limited to 'tvix/eval/src/vm.rs')
| -rw-r--r-- | tvix/eval/src/vm.rs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs index 17a7e0ce2758..400d85adac30 100644 --- a/tvix/eval/src/vm.rs +++ b/tvix/eval/src/vm.rs @@ -538,8 +538,9 @@ impl<'o> VM<'o> { OpCode::OpConcat => { let rhs = fallible!(self, self.pop().to_list()); - let lhs = fallible!(self, self.pop().to_list()); - self.push(Value::List(lhs.concat(&rhs))) + let mut lhs = fallible!(self, self.pop().to_list()).into_vec(); + lhs.extend_from_slice(&rhs); + self.push(Value::List(NixList::from(lhs))) } OpCode::OpInterpolate(Count(count)) => self.run_interpolate(count)?, |