[ruby-core:117421] [Ruby master Misc#20406] Question about Regexp encoding negotiation
From:
"shyouhei (Shyouhei Urabe) via ruby-core" <ruby-core@...>
Date:
2024-04-03 06:10:50 UTC
List:
ruby-core #117421
Issue #20406 has been updated by shyouhei (Shyouhei Urabe).
Seems like a real bug to me.
```
% docker run --rm -it -e 'ALL_RUBY_SINCE=ruby-1.8.7' rubylang/all-ruby ./all-ruby -e 'p(/#{} a/e.encoding)'
ruby-1.8.7 -e:1: undefined method `encoding' for / a/e:Regexp (NoMethodError)
exit 1
...
ruby-1.8.7-p374 -e:1: undefined method `encoding' for / a/e:Regexp (NoMethodError)
exit 1
ruby-1.9.0-0 #<Encoding:EUC-JP>
...
ruby-1.9.2-preview1 #<Encoding:EUC-JP>
ruby-1.9.2-preview3 #<Encoding:US-ASCII>
...
ruby-3.3.0 #<Encoding:US-ASCII>
```
----------------------------------------
Misc #20406: Question about Regexp encoding negotiation
https://bugs.ruby-lang.org/issues/20406#change-107796
* Author: andrykonchin (Andrew Konchin)
* Status: Open
----------------------------------------
I am wondering what are the rules to calculate Regexp literal encoding in case an encoding modifier is specified.
>From the documentstion:
> By default, a regexp with only US-ASCII characters has US-ASCII encoding:
> ...
> A regular expression containing non-US-ASCII characters is assumed to use the source encoding. This can be overridden with one of the following modifiers.
> //n ...
> //u ...
> //e ...
> //s ...
Looking at the following examples I would assume that these rules are followed except one case:
```ruby
p /\xc2\xa1/e .encoding # EUC-JP
p /#{ }\xc2\xa1/e .encoding # EUC-JP
p /a/e .encoding # EUC-JP
p /a #{} a/e .encoding # EUC-JP
p /#{} a/e .encoding # US-ASCII
```
The last Regexp `/#{} a/e` is supposed to have `EUC-JP` encoding but has `US-ASCII`. So I am wondering what rule is applied in this case.
--
https://bugs.ruby-lang.org/
______________________________________________
ruby-core mailing list -- ruby-core@ml.ruby-lang.org
To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/