basic pattern match

Community Support
1

I’m trying to create a function that will search a string for anexpression such as "zz(aa|bb)zz"so “yyzzaazzau” sss “zz(aa|bb)zz” would return ,2 (similar to the ssfunction) just with the inclusion of OR and matching two charactersinstead of just single characters.My first solution was terrible as I created a list of all possibleacceptable combinations of the string from the expression. So for myexample -“zzaazz”"zzbbzz"but it spiraled out of control when I added more complex pattern -“zz(aa|bb|cc)xx(dd|cc)uu” would lead to six possible combinationsetc…As my initial idea failed, if anybody could suggest a particular angleto attempt this from I’d appreciate it!Thanks

2

Hi,

If q external libraries are an option for you, please have a look at some regular expression ports (PCRE) to q;

http://q.o.potam.us/?p=pcre

http://thesweeheng.wordpress.com/2008/07/14/regular-expressions-for-q/

This solution opens ‘pattern matching’ doors wider and is very neat.

Cheers,
Patryk

3

You can also port the boost library boost.regex to Q.

Am 27.03.2012 09:41, schrieb Patryk Bukowinski:

Hi,

If q external libraries are an option for you, please have a look at some regular expression ports (PCRE) to q;

http://q.o.potam.us/?p=pcre

http://thesweeheng.wordpress.com/2008/07/14/regular-expressions-for-q/

This solution opens ‘pattern matching’ doors wider and is very neat.

Cheers,
Patryk

4

PCRE is very useful, thanks!I’m also attempting to port the boost.regex library to Q, however I’mhaving some problems extending Q with C++.just writing a basic c++ program along the lines of#include "k.h"K f(K x){ return ki(10);}On linux I’m compiling usinggcc -I /path/my/folder -shared -fPIC myfile.cpp -o ~/q/l32/myfile.soHowever, when I run func:myfile 2:(func;1) I just get undefinedsymbol f, no matter what I try.Thanks, OllieOn Mar 28, 8:26?pm, Kim Kuen Tang <kuent…> wrote:> You can also port the boost library boost.regex to Q.>> Am 27.03.2012 09:41, schrieb Patryk Bukowinski:>>>>>>>>>> > Hi,>> > If q external libraries are an option for you, please have a look at> > some regular expression ports (PCRE) to q;>> >http://q.o.potam.us/?p=pcre&gt;&gt; >http://thesweeheng.wordpress.com/2008/07/14/regular-expressions-for-q/&gt;&gt; > This solution opens ‘pattern matching’ doors wider and is very neat.>> > Cheers,> > Patryk>> > On Mar 23, 2012 1:38 PM, “oli.l” <ollie920…> > mailto:ollie920...> wrote:>> > ? ? I’m trying to create a function that will search a string for an> > ? ? expression such as “zz(aa|bb)zz”>> > ? ? so “yyzzaazzau” sss “zz(aa|bb)zz” would return ,2 (similar to the ss> > ? ? function) just with the inclusion of OR and matching two characters> > ? ? instead of just single characters.>> > ? ? My first solution was terrible as I created a list of all possible> > ? ? acceptable combinations of the string from the expression. So for my> > ? ? example -> > ? ? “zzaazz”> > ? ? “zzbbzz”> > ? ? but it spiraled out of control when I added more complex pattern -> > ? ? “zz(aa|bb|cc)xx(dd|cc)uu” would lead to six possible combinations> > ? ? etc…>> > ? ? As my initial idea failed, if anybody could suggest a particular angle> > ? ? to attempt this from I’d appreciate it!>> > ? ? Thanks>> > ? ? –> > ? ? You received this message because you are subscribed to the Google> > ? ? Groups “Kdb+ Personal Developers” group.> > ? ? To post to this group, send email to> > ? ? personal-kdbplus@googlegroups.com> > ? ? mailto:personal-kdbplus.> > ? ? To unsubscribe from this group, send email to> > ? ? personal-kdbplus+unsubscribe@googlegroups.com> > ? ? mailto:personal-kdbplus.> > ? ? For more options, visit this group at> > ? ?http://groups.google.com/group/personal-kdbplus?hl=en.&gt;&gt; > –> > You received this message because you are subscribed to the Google> > Groups “Kdb+ Personal Developers” group.> > To post to this group, send email to personal-kdbplus@googlegroups.com.> > To unsubscribe from this group, send email to> > personal-kdbplus+unsubscribe@googlegroups.com.> > For more options, visit this group at> >http://groups.google.com/group/personal-kdbplus?hl=en.</mailto:personal-kdbplus></mailto:personal-kdbplus></mailto:ollie920…></ollie920…></kuent…>

5

#include “k.h”
extern “C” K f(K x){
 return ki(10);
}