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

[Terrence Enger <tenger@xxxxxxxxxxxxxxxx>]

On Mon, 2009-08-03 at 12:22 -0500, Scott Klement wrote:
> Hi Terry,
>
> Have you read the following (from regexec topic in the "ILE C Runtime 
> Library" manual):
>
>     If subexpression i is contained within another subexpression j, and i
>     is not contained within any other subexpression that is contained
>     within j, and a match of subexpression j is reported in pmatch[j],
>     then the match or non-match of subexpression i reported in pmatch[i]
>     will be as described in 1. and 2. above, but within the substring
>     reported in pmatch[j] rather than the whole string.

No, I should have been following that.  Thank you.

In a simple case, I see that behaviour:  regex "nu((t*)(i))" and string
"nuttin" return
    rm_so  rm_eo
    -----  -----
    2      5
    0      2
    2      3

Introduction of a set of parentheses earlier in the regex should not, as
I read it, change the result returned for the last two subexpressions.
But the result for regex "n(u)((t*)(i))" is
ï    rm_so  rm_eo
    -----  -----
    1      2
    2      5
    1      3
    3      4

Thank you for your help, Scott.  Any further thoughts?

Terry.

> Terrence Enger wrote:
> > However, the two testers disagree about submatches for
> > regex ï"(n)(u)((t*)(i))" and test string "nuttin" ...
> >     web     mine
> >     ----    ----
> > ï    n       n
> >     u       u
> >     tti     ttu
> >     tt      ut
> >     i       t