YAML::XS perl/regexp (?u:(?u:

Boldra has asked for the wisdom of the Perl Monks concerning the following question:

My YAML being read is

---
NODE:
  match: !!perl/regexp (?^ui:OK\ Server\ Connection\ 1\.001)
[download]

After loading/dumping it looks like this

---
NODE:
  match: !!perl/regexp (?^u:(?^ui:OK\ Server\ Connection\ 1\.001))
[download]

After 20 load/dump cycles it looks like this:

---
NODE:
  match: !!perl/regexp (?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?
+^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^ui:OK\
    Server\ Connection\ 1\.001)))))))))))))))))))))
[download]

My test:

perl -MYAML::XS -E 'my $y=YAML::XS::Load(q{---\nNODE:\n  match: !!perl
+/regexp (?i-xsm:OK\ Server\ Connection\ 1\.001)}); for(1..20) { $y=Lo
+ad(Dump($y)) }; say Dump($y)'
[download]

$YAML::XS::VERSION = 0.66
perl v5.24.3

If I let it run long enough, eventually the parser breaks down. Does anyone have any suggestions?

- Boldra

Comment on YAML::XS perl/regexp (?u:(?u: Select or Download Code

Replies are listed 'Best First'.
Re: YAML::XS perl/regexp (?u:(?u: by Boldra (Deacon) on Dec 05, 2017 at 12:49 UTC
My memory... :( I hit this already years ago YAML: regex stringification has changed - Boldra	[reply]
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Re: YAML::XS perl/regexp (?u:(?u: by ikegami (Patriarch) on Dec 05, 2017 at 15:32 UTC
YAML should store the pattern (`( re::regexp_pattern($re) )[0]`) and the modifiers (`( re::regexp_pattern($re) )[1]`) separately.	[reply] [d/l] [select]
Re^2: YAML::XS perl/regexp (?u:(?u: by shmem (Chancellor) on Dec 06, 2017 at 22:07 UTC
YAML should store the pattern (( `re::regexp_pattern($re) )[0]` ) and the modifiers ( `( re::regexp_pattern($re) )[1]` ) separately. ...and YAML::XS should make use of `XS(XS_re_regexp_pattern)` in `universal.c` to achieve that. Inevitably, this raises backcompat issues. perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'	[reply] [d/l] [select]
Re^3: YAML::XS perl/regexp (?u:(?u: by ikegami (Patriarch) on Dec 07, 2017 at 22:45 UTC
and YAML::XS should make use of XS(XS_re_regexp_pattern) in universal.c And how does one do that? `XS(XS_re_regexp_pattern)` creates the Perl sub `re::regexp_pattern`, so that's a very weird way of saying that YAML::XS should call Perl sub `re::regexp_pattern`. Inevitably, this raises backcompat issues. This can be addressed by storing them as a different type than `perl/regexp` (`perl/regexp_plus_mods`?).	[reply] [d/l] [select]
Re^4: YAML::XS perl/regexp (?u:(?u: by tinita (Parson) on Dec 08, 2017 at 15:48 UTC
Re^5: YAML::XS perl/regexp (?u:(?u: by ikegami (Patriarch) on Dec 19, 2017 at 19:32 UTC
Re^2: YAML::XS perl/regexp (?u:(?u: by tinita (Parson) on Dec 08, 2017 at 16:54 UTC
It would be possible to store a regex as a sequence and use the same tag for it: `--- re1: !!perl/regexp (?^usi:pattern) re2: !!perl/regexp [ pattern, isu ]` [download] For perl 5.8 the old behaviour could be used. This could be done for YAML and YAML::XS. Possibly also for YAML::Syck, which has the same problem, but I would have to ask Todd, the maintainer.	[reply] [d/l]
Re^3: YAML::XS perl/regexp (?u:(?u: by ikegami (Patriarch) on Dec 19, 2017 at 19:29 UTC
You can add understanding of `!!perl/regexp [ pattern, isu ]` at any time, but backwards compatibility requires making the generation of that an option. Eventually, once support has been established, it could default to the new method.	[reply] [d/l]
Re^4: YAML::XS perl/regexp (?u:(?u: by tinita (Parson) on Dec 19, 2017 at 21:17 UTC
Re^5: YAML::XS perl/regexp (?u:(?u: by ikegami (Patriarch) on Dec 20, 2017 at 15:57 UTC
Some notes below your chosen depth have not been shown here
Re: YAML::XS perl/regexp (?u:(?u: by tinita (Parson) on Dec 08, 2017 at 17:05 UTC
See my quick and dirty fix in https://github.com/ingydotnet/yaml-libyaml-pm/pull/70	[reply]
Re: YAML::XS perl/regexp (?u:(?u: by Anonymous Monk on Dec 05, 2017 at 10:49 UTC
Reporte upstream :) https://github.com/ingydotnet/yaml-libyaml-pm/issues/64	[reply] [d/l]
Re^2: YAML::XS perl/regexp (?u:(?u: by tinita (Parson) on Dec 16, 2017 at 20:31 UTC
Issue 64 should be fixed by https://github.com/ingydotnet/yaml-libyaml-pm/pull/71	[reply]
Re^2: YAML::XS perl/regexp (?u:(?u: by tinita (Parson) on Dec 06, 2017 at 23:06 UTC
I think issue 64 is not related to this one Edit: I thought you meant "`[`already] Reported upstream"	[reply] [d/l]
Re^3: YAML::XS perl/regexp (?u:(?u: by Anonymous Monk on Dec 06, 2017 at 23:52 UTC
I think issue 64 is not related to this one good observation, hence recommend to report it :)	[reply]


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