[ruby-core:99722] [Ruby master Bug#17030] Enumerable#grep{_v} should be optimized for Regexp
From:
marcandre-ruby-core@...
Date:
2020-08-27 02:10:00 UTC
List:
ruby-core #99722
Issue #17030 has been updated by marcandre (Marc-Andre Lafortune).
Dan0042 (Daniel DeLorme) wrote in #note-17:
> Maybe not impossible, but personally I wouldn't want to code that kind of analysis when a simple approach is enough for >90% of cases, and guaranteed to be bug-free.
Agreed
> > There will be other false positives: `str.gsub(regexp, &block)`. That's not a real issue, simply assume that `block` will want access to `Regexp.last_match`.
>
> Actually... `block` does not have access to `Regexp.last_match` (unless you created the block in the same scope as the gsub operation, but that would be unusual)
You are right, my bad.
----------------------------------------
Bug #17030: Enumerable#grep{_v} should be optimized for Regexp
https://bugs.ruby-lang.org/issues/17030#change-87213
* Author: marcandre (Marc-Andre Lafortune)
* Status: Open
* Priority: Normal
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN
----------------------------------------
Currently,
```ruby
array.select { |e| e.match?(REGEXP) }
```
is about three times faster and six times more memory efficient than
```ruby
array.grep(REGEXP)
```
This is because `grep` calls `Regexp#===`, which creates useless `MatchData`.
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