For strings of any notable length, Fx Hash outperforms FNV. Rustc also
moved to this hash function and noticed performance
improvements. Fortunately, as was accounted for in the design, this was a
trivial switch.
Here are some benchmarks to back up that claim:
test hash_set::fnv::with_all_new_1000 ... bench: 133,096 ns/iter (+/- 1,430)
test hash_set::fnv::with_all_new_1000_with_capacity ... bench: 82,591 ns/iter (+/- 592)
test hash_set::fnv::with_all_new_rc_str_1000_baseline ... bench: 162,073 ns/iter (+/- 1,277)
test hash_set::fnv::with_one_new_1000 ... bench: 37,334 ns/iter (+/- 256)
test hash_set::fnv::with_one_new_rc_str_1000_baseline ... bench: 18,263 ns/iter (+/- 261)
test hash_set::fx::with_all_new_1000 ... bench: 85,217 ns/iter (+/- 1,111)
test hash_set::fx::with_all_new_1000_with_capacity ... bench: 59,383 ns/iter (+/- 752)
test hash_set::fx::with_all_new_rc_str_1000_baseline ... bench: 98,802 ns/iter (+/- 1,117)
test hash_set::fx::with_one_new_1000 ... bench: 42,484 ns/iter (+/- 1,239)
test hash_set::fx::with_one_new_rc_str_1000_baseline ... bench: 15,000 ns/iter (+/- 233)
test hash_set::with_all_new_1000 ... bench: 137,645 ns/iter (+/- 1,186)
test hash_set::with_all_new_rc_str_1000_baseline ... bench: 163,129 ns/iter (+/- 1,725)
test hash_set::with_one_new_1000 ... bench: 59,051 ns/iter (+/- 1,202)
test hash_set::with_one_new_rc_str_1000_baseline ... bench: 37,986 ns/iter (+/- 771)
This will be used for generating the common tests between HashSet and
HashMap implementations.
This is my first macro in Rust. There does not seem to be a way to
concatenate identifiers (!), so I'm placing them within modules
instead. That ended up working out just fine, since then I can use a type
to provide the SUT.
This is missing two key things that I'll add shortly: a HashMap-based one
for use in the ASG for node mapping, and an entry-based system for
manipulations.
This has been a nice start for exploring various aspects of Rust
development, as well as conventions that I'd like to implement. In
particular:
- Robust documentation intended to guide people through learning the
necessary material about the compiler, as well as related work to
rationalize design decisions;
- Benchmarks;
- TDD;
- And just getting used to Rust in general.
I've beat this one to death, so I'll commit this and make smaller changes
going forward to show how easily it can evolve.
(This module was originally named `intern` but this commit and those that
follow rewrote it to `sym`.)
This is enabled by default in nightly, and is not available at all in
stable. Considering the PITA that it will be to go back and rewrite docs to
use the new format, and how important of a feature this is, we will just
make use of it now.
Given that developers should be doing TDD and therefore running this target
frequently, this has the effect of providing immediate feedback when
formatting is needed and outputting a diff. Developers will then quickly
understand what changes need to be made to avoid future issues (and can run
`cargo fmt` to fix it), at which point they'll rarely ever encounter
formatting errors.
The original purpose was to ensure pipelines fail when the formatter has not
been run.
This makes use of Petgraph for representing the dependency graph and uses a
separate data structure for both string interning and indexing by symbol
name.
This is garbage code. Do not use it. It is intentionally throwaway.
While I've researched Rust, I haven't actually _used_ it for a project, so
this is a combination of me exploring various ways of accomplishing the
problem and forcing myself to learn certain aspects of the language.
I'll likely be using petgraph, and this also currently lacks symbol
abstractions. This commit also performs far too much heap allocation
copying strings around. But it _does_ perform the topological sort.
Since this only stores the symbol name, it lacks enough information about
the symbol to perform a proper linking.
Mike Gerwitz