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digitalmars.D.learn - Re: Fuzzy string matching?

reply dsmith <ds nomail.com> writes:
Could you demonstrate how to use std.regex for pattern matching, preferably
with a bool method?

My usage of std.regex.match yields this error:
core.exception.AssertError /usr/include/d/dmd/phobos/std/regex.d(1796):
4294967295 .. 4294967295 vs. 5

My usage is:     auto m = match(long_string, regex(str));
                        writeln(m.hit);


== Repost the article of Jonathan M Davis (jmdavisProg gmx.com)
== Posted at 2011/07/16 01:08 to digitalmars.D.learn

OnSaturday16July201105:07:38dsmithwrote:
Untilrecently,youcouldeasilyusestd.regexp.search(target_string,
find_string),butregexpisapparentlynolongerinphobos.Iseeka
simplesubstitute.std.algorithm.canFindmightwork,asitisbool.

Maybetrysomethinglike:

foreach(str;strings)
foreach(fls;system_files)
if(std.algorithm.canFind(fls,str))//usageneedsverification
             str~=".ext";

std.regexisstd.regexp'sreplacement. -JonathanMdavis
Jul 15 2011
next sibling parent Jonathan M Davis <jmdavisProg gmx.com> writes:
On Saturday 16 July 2011 06:17:56 dsmith wrote:
 Could you demonstrate how to use std.regex for pattern matching, preferably
 with a bool method?
 
 My usage of std.regex.match yields this error:
 core.exception.AssertError /usr/include/d/dmd/phobos/std/regex.d(1796):
 4294967295 .. 4294967295 vs. 5
 
 My usage is:     auto m = match(long_string, regex(str));
                         writeln(m.hit);

I'm afraid that I've never used either std.regexp or std.regex, so I'm not familiar with the usage of either one. There's every chance that this is a bug rather than misuse on your part. I'd advise posting a question about it separately (so that people are more likely to see it) with an appropriate subject, and there's a decent chance that someone who's actually familiar with std.regex will answer your question. - Jonathan M Davis
Jul 15 2011
prev sibling parent Dmitry Olshansky <dmitry.olsh gmail.com> writes:
On 16.07.2011 10:17, dsmith wrote:
 Could you demonstrate how to use std.regex for pattern matching, preferably
with a bool method?

 My usage of std.regex.match yields this error:
core.exception.AssertError /usr/include/d/dmd/phobos/std/regex.d(1796):
4294967295 .. 4294967295 vs. 5

 My usage is:     auto m = match(long_string, regex(str));
                          writeln(m.hit);

Your and apparently an awful lot of people hit this, the thing is that .hit method is returning _matched slice_ of string if there is a match and asserts otherwise. (there is also issue of this assert having message is of a _very_ poor quality) As it stands now regex works like ranges: you need to check if it was empty then use it, so if all you want to do is a test: auto m = match(long_string, regex(str)); writeln(!m.empty); // substitute for "there was match" Thinking more about this, it should be in synopsis part of std.regex in docs on d-p-l.org. Along with something like: foreach(m; match("abc", regex("\w", "g")) //uses range syntax to iterate over all matches (so empty is checked) writeln(m.hit); // here m.hit is guaranteed to hold something (and not asserting)
 == Repost the article of Jonathan M Davis (jmdavisProg gmx.com)
 == Posted at 2011/07/16 01:08 to digitalmars.D.learn

 On�Saturday�16�July�2011�05:07:38�dsmith�wrote:
 �Until�recently,�you�could�easily�use�std.regexp.search(target_string,
 �find_string),�but�regexp�is�apparently�no�longer�in�phobos.��I�seek�a
 �simple�substitute.��std.algorithm.canFind�might�work,�as�it�is�bool.
 �Maybe�try�something�like:

 �foreach(str;�strings)
 �����foreach(fls;�system_files)
 ���������if(std.algorithm.canFind(fls,�str))���//�usage�needs�verification
              str�~=�".ext";

-�Jonathan�M�davis

-- Dmitry Olshansky
Jul 16 2011