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Postings from October 2010
Well, I can think of a few that have material of this sort, but
nothing that is regex specific.
The "Red Dragon Book" (Compilers: Principles, Techniques, and Tools)
is the one I can name off the top of my head...
The thing is the strict definition of regular expressions allows for
only a very limited set of operators, and does not provide many of the
features that most people these days would consider to be an important
aspect of a regex engines job, and not only that but the generally
expected semantics of a "true" regular expression engine differ from
engines generally used in practice.
For instance, the semantics of "leftmost-longest" and things like
capturing, and back-references are not part of what the academic
definition of regular-expression would include. So, the academic
literature is generally not applicable to real life use of real life
regex-engines in practice, as it is unlikely the engine is a true
"regular expression" engine. This is the case with Perl engine, which
probably has more in common with something like prolog than it has in
common with a DFA/NFA.
So I guess, the point is sort of that the theory and practice have
kind of diverged....
cheers,
Yves
2010/10/27 ольга крыжановская <olga.kryzhanovska@gmail.com>:
> Is there a better book which covers the theoretical aspect?
>
> Olga
>
> 2010/10/27 demerphq <demerphq@gmail.com>:
>> 2010/10/27 David Golden <xdaveg@gmail.com>:
>>> Yes. You will not find a better book on regular expressions. It is the bibie.
>>
>> Well, it is a bit weak on the theoretical aspect of regexen. However
>> it more than makes up for it with practical utility.
>>
>> cheers,
>> yves
>>
>>
>> --
>> perl -Mre=debug -e "/just|another|perl|hacker/"
>>
>
>
>
> --
> , _ _ ,
> { \/`o;====- Olga Kryzhanovska -====;o`\/ }
> .----'-/`-/ olga.kryzhanovska@gmail.com \-`\-'----.
> `'-..-| / http://twitter.com/fleyta \ |-..-'`
> /\/\ Solaris/BSD//C/C++ programmer /\/\
> `--` `--`
>
--
perl -Mre=debug -e "/just|another|perl|hacker/"
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