Issue #17030 has been updated by marcandre (Marc-Andre Lafortune).


Dan0042 (Daniel DeLorme) wrote in #note-15:
> But static analysis has other limits

Good example but it is easily resolved: assume `v` isn't a Regexp and we may get a false positive, which is not a big issue. 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`. I'm really only worried about false negatives... Any other example comes to mind?

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Bug #17030: Enumerable#grep{_v} should be optimized for Regexp
https://bugs.ruby-lang.org/issues/17030#change-87204

* 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) }

# about 3x faster and 6x more memory efficient than
array.grep(REGEXP)
```

This is because `grep` calls `Regexp#===` which creates useless `MatchData`



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