[Issue 7551] Regex parsing bug for right bracket in character class
https://issues.dlang.org/show_bug.cgi?id=7551 --- Comment #7 from github-bugzi...@puremagic.com --- Commits pushed to master at https://github.com/D-Programming-Language/phobos https://github.com/D-Programming-Language/phobos/commit/afd16eac09d8178d47d2e39ba8fe87c765369fc7 Fix issue 7551 - Regex parsing bug for right bracket in character class https://github.com/D-Programming-Language/phobos/commit/0ce66bc7aa9aee44757bda5b6102b8180dda3b19 Merge pull request #4161 from DmitryOlshansky/issue-11765 Fix issue 7551 - Regex parsing bug for right bracket in character class --
[Issue 7551] Regex parsing bug for right bracket in character class
http://d.puremagic.com/issues/show_bug.cgi?id=7551 --- Comment #2 from Magnus Lie Hetland mag...@hetland.org 2012-02-27 00:44:59 PST --- It did exist in the previous version -- my code broke with the new regexp engine, but worked before :-) If this is a conscious choice, then that's totally fine by me. Special cases aren't the right way to go when the general mechanism works. I had some trouble getting this to work (did something like what you wrote here, which won't work -- but double-escaping does, of course), so I ended up with using the or-operator, which was kind of hackish ;-) So, yeah, I guess I retract my bug report :- As for other languages: Yeah, I think this is pretty common. E.g., Python (http://docs.python.org/library/re.html) and in Perl and Perl-compatible regexps, as used in all kinds of places, such as PHP, Apache, Safari, … (http://www.php.net/manual/en/regexp.reference.character-classes.php). So I think the place member end brackets as first character is the industry standard behavior. But as a compromise: Perhaps a useful error message pointing out the escape thing could be added? Or it could be explicitly pointed out in a note in the documentation (to avoid special-casing the error code)? I think some kind of least surprise handling for people coming from basically anywhere else might be useful ;-) -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 7551] Regex parsing bug for right bracket in character class
http://d.puremagic.com/issues/show_bug.cgi?id=7551 --- Comment #3 from Magnus Lie Hetland mag...@hetland.org 2012-02-27 00:51:18 PST --- This whole thing goes for start brackets, too, I guess. As far as I can see, they, too, must be escaped when used inside character classes, now. This follows from the definition in the docs, for sure, but wasn't entirely obvious to me -- especially given that it worked before. (I.e., that was another thing that broke in my code recently, when upgrading.) -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 7551] Regex parsing bug for right bracket in character class
http://d.puremagic.com/issues/show_bug.cgi?id=7551 Dmitry Olshansky dmitry.o...@gmail.com changed: What|Removed |Added Severity|normal |enhancement --- Comment #4 from Dmitry Olshansky dmitry.o...@gmail.com 2012-02-27 02:36:06 PST --- Full backwards compatibility looked like a nice idea at start. I'm increasingly regret that decision, as things still got broken as I had to add new features that block some undocumented behavior. Ehm escape sequences were partly broken in 2.057 ... sorry about that. BTW this page shows that [ and ] should be escaped, and not a single word on it used as first character (unlike '-' that is supported). http://www.php.net/manual/en/regexp.reference.character-classes.php About Python, heh, I'm eager to see how would they go about adding set operations without breaking compatibility (they count [ as plain '[' in the middle of charset). I guess a brand new module if it they ever will. But as a compromise: Perhaps a useful error message pointing out the escape thing could be added? Or it could be explicitly pointed out in a note in the documentation (to avoid special-casing the error code)? I think some kind of least surprise handling for people coming from basically anywhere else might be useful ;-) Hm.. that's a good idea. Hereby it's an enhacement request ;) -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 7551] Regex parsing bug for right bracket in character class
http://d.puremagic.com/issues/show_bug.cgi?id=7551 --- Comment #6 from Dmitry Olshansky dmitry.o...@gmail.com 2012-02-27 05:18:12 PST --- (In reply to comment #5) Quoting Dmitry: BTW this page shows that [ and ] should be escaped, and not a single word on it used as first character (unlike '-' that is supported). http://www.php.net/manual/en/regexp.reference.character-classes.php Huh? Did you read the first paragraph…?-) Searching gets the better of me :( I 'greped' for [ Quoted, for your convenience (my highlight): An opening square bracket introduces a character class, terminated by a closing square bracket. A closing square bracket on its own is not special. **If a closing square bracket is required as a member of the class, it should be the first data character in the class** (after an initial circumflex, if present) or escaped with a backslash. It says so right there, no? This is the way it's been in several languages I've used throughout the years. I guess they just didn't have escaping inside character classes in the olden days ;-) Apparently it's one of these historical kind of things. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 7551] Regex parsing bug for right bracket in character class
http://d.puremagic.com/issues/show_bug.cgi?id=7551
Dmitry Olshansky dmitry.o...@gmail.com changed:
What|Removed |Added
CC||dmitry.o...@gmail.com
--- Comment #1 from Dmitry Olshansky dmitry.o...@gmail.com 2012-02-24
11:28:25 PST ---
It perfectly fine to use escapes for special characters:
import std.regex;
void main() {
auto r = regex([\]]);
}
The reason for killing first bracket doesn't count rule (if ever knew it
existed)
is that new regex allows doing things like
[[abc0-9]--[bcd||1-9]]
i.e. set operations
the above should get you [bc0], it's more useful with \p{xxx} things.
Basically braces do matter more now.
But this many other languages... (or better libraries) - which ones? Unless
there is strong precident I'm not doing another special case.
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