https://github.com/rust-lang/rust http://git.dreamy.place/mirrors/rust/atom?h=1.34.0 2019-02-12T12:10:10+00:00 2019-02-12T12:10:10+00:00 bors bors@rust-lang.org 2019-02-12T12:10:10+00:00 urn:sha1:c84e7976423bb910bb5eb5eecffc7e33a897a97f Require a list of features in `#[allow_internal_unstable]` The blanket-permission slip is not great and will likely give us trouble some point down the road. 2019-02-11T14:08:17+00:00 Oliver Scherer github35764891676564198441@oli-obk.de 2019-02-07T13:19:06+00:00 urn:sha1:b681433b9d40ce1d851d22bedb7ccb483bedda06 2019-02-11T14:08:16+00:00 Oliver Scherer github35764891676564198441@oli-obk.de 2019-02-03T11:55:00+00:00 urn:sha1:d3c212c5527f901fcb44d59d031695248762c340 2019-02-10T07:13:30+00:00 Taiki Endo te316e89@gmail.com 2019-02-10T07:13:30+00:00 urn:sha1:2be0993c4e219994b355a06e82394c966a2cfa5d 2019-02-06T13:55:03+00:00 Taiki Endo te316e89@gmail.com 2019-02-06T13:55:03+00:00 urn:sha1:44b2cc0941e63cb8b12fd3a361d8eb8564504a73 2019-02-05T22:06:27+00:00 Nicholas Nethercote nnethercote@mozilla.com 2019-02-05T04:20:55+00:00 urn:sha1:9fcb1658ab13a7f722e4747c5a4b691291e88a3b This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file. 2018-12-26T04:08:33+00:00 Mark Rousskov mark.simulacrum@gmail.com 2018-12-25T15:56:47+00:00 urn:sha1:2a663555ddf36f6b041445894a8c175cd1bc718c 2018-12-09T22:31:27+00:00 Nicholas Nethercote nnethercote@mozilla.com 2018-11-28T21:52:22+00:00 urn:sha1:ecf6cd4b3c8d4e04e47f1e49a6a8fb4cda19700e 2018-09-28T03:52:53+00:00 Josh Stone jistone@redhat.com 2018-09-26T21:26:46+00:00 urn:sha1:ce034951fb907c8aa6abd5e6e04769e5e628953c 2018-09-26T08:43:37+00:00 ljedrz ljedrz@gmail.com 2018-08-30T09:42:16+00:00 urn:sha1:130a32fa7259d348dc3a684b38e688da398c30bb