[#122973] [PATCH] Add Gem.default_install — Felipe Contreras via ruby-core <ruby-core@...>
We need a way to enable user installs by default so that tools like
3 messages
2025/08/17
[ruby-core:123026] [Ruby Feature#21532] Define most of Pathname in Ruby code
From:
"akr (Akira Tanaka) via ruby-core" <ruby-core@...>
Date:
2025-08-21 12:58:21 UTC
List:
ruby-core #123026
Issue #21532 has been updated by akr (Akira Tanaka).
Ok. Merge it.
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Feature #21532: Define most of Pathname in Ruby code
https://bugs.ruby-lang.org/issues/21532#change-114336
* Author: Eregon (Benoit Daloze)
* Status: Open
* Assignee: Eregon (Benoit Daloze)
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There was discussion in #17473 and before to define most of Pathname in Ruby code and not in the C extension.
I have made a PR to achieve that: https://github.com/ruby/pathname/pull/57
I would like to merge it soon to avoid conflicts.
Once upon a time, Pathname was pure-Ruby: https://github.com/ruby/ruby/blob/95bc02237635d3fe42532bfe53038257575cee75/lib/pathname.rb
This PR goes back to that, and reuses that original Ruby code, but keeps the C extension implementation of `<=>` and `sub` as those two are significantly faster.
The other Pathname methods are actually faster in Ruby than in C, because all these methods just do `rb_funcall()` and `rb_ivar_get()` and those in C code have no inline cache, but the corresponding method calls and `@path` have inline caches in Ruby code.
https://railsatscale.com/2023-08-29-ruby-outperforms-c/ is an explanation of that.
Therefore having Pathname defined in Ruby seems a clear win for many reasons:
* Much clearer implementation, so easier to read what the code does
* Easier to maintain
* Safer (no risk of accessing out of bounds memory or e.g. passing the wrong number of arguments to `rb_funcall`)
* Significantly faster, because of these inline caches (more details in https://github.com/ruby/pathname/pull/57#issue-3234862768):
| Speedup (this branch / master) | ruby 3.4.2 | ruby 3.4.2 + YJIT |
| --- | --- | --- |
| `Pathname.new(".")` | 1.02x | 1.19x |
| `Pathname#directory?` | 1.03x | 1.06x |
| `Pathname#to_s` | 1.85x | 2.38x |
* Better for JITs as they can optimize this, notably `...` vs the C extension being a blackbox
* Works on JRuby (which does not support C extensions)
* Works on TruffleRuby (some Ruby C API functions that the extension uses are not supported on TruffleRuby)
--
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