Re: [Fwd: regular expressions, I am puzzled]

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

Terry,

Your results are exactly what I would've expected.  You didn't explain 
what you are trying to accomplish, or why these aren't the results you 
wanted, or what results you _do_ want, so I'm not sure how to help you 
further.



Terrence Enger wrote:
> I have not seen this arrive from the list.  I beg your pardon if it
> appears twice.
>
> -------- Forwarded Message --------
> From: Terrence Enger <tenger@xxxxxxxxxxxxxxxx>
> Reply-To: tenger@xxxxxxxxxxxxxxxx
> To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
> Subject: regular expressions, I am puzzled
> Date: Thu, 30 Jul 2009 14:35:37 -0400
>
> Greetings,
>
> There has been a bit of discussion about regular expressions on
> c400-l, but I am bringing my question here because I do not know
> that my question has anything to do with the programming
> language.  On the other hand, the regular expression APIs are
> documented in SC41-5607-03 "ILE C/C++ Runtime Library Functions",
> and I transcribed some stuff from QSYSINC/H(REGEX); so ya takes
> yur chances.  For what it's worth, I am using V5R2, ILE RPG, and
> extended regular expressions.
>
> My regular expression exerciser is giving results which
> contradict both my preconceptions and the web-based exercisers
> which I have tried.  First, a test giving the results I expect.
> Reported from and to numbers are rm_so and rm_eo within the array
> of regmatch_t returned from regexec().
>
>
> Previous result         0         1         2         3         4         
>                         0....+....0....+....0....+....0....+....0....+....
>   Input string . . . :  nuttin                                            
>   Regular expression :  (n)(u)(t*)(i)                                     
>   Matches . . . . . .:  Sub#    Details                     Starting      
>                         ----    ---------------------       --------
>                            0    from 0 to 5, length 5       nutti         
>                            1    from 0 to 1, length 1       n             
>                            2    from 1 to 2, length 1       u             
>                            3    from 2 to 4, length 2       tt            
>                            4    from 4 to 5, length 1       i             
>
> But when I add an extra set of parentheses, the offsets of
> subexpressions in that added subexpression sometimes are somewhat
> reduced.
>
>
> Previous result         0         1         2         3         4         
>                         0....+....0....+....0....+....0....+....0....+....
>   Input string . . . :  nuttin                                            
>   Regular expression :  (n)(u)((t*)(i))                                   
>   Matches . . . . . .:  Sub#    Details                     Starting      
>                         ----    ---------------------       --------
>                            0    from 0 to 5, length 5       nutti         
>                            1    from 0 to 1, length 1       n             
>                            2    from 1 to 2, length 1       u             
>                            3    from 2 to 5, length 3       tti           
>                            4    from 1 to 3, length 2       ut            
>                            5    from 3 to 4, length 1       t             
>
> Within the section on extended regular expressions in "The Single
> UNIX (R) Specification, Version 2, Regular Expressions"
> <http://www.opengroup.org/onlinepubs/007908799/xbd/re.html>, I
> have looked at each cause of undefined behaviour, and I don't see
> that any of them applies to what I am doing.
>
> Do these results make any sense?  Or, are there any ideas about
> what I could be doing wrong?  Should anybody care, perchance, I
> can provide the source for my exerciser program.
>
> Thank you, for your attention.
>
> Cheers,
> Terry.