[re2c-devel] interest in a tagged-DFA implementation?

[Serguei M. <sma...@re...>]

Dear all,

I previously wrote to you about the recent incorporation of re2c in Systemtap 2.1 as a regular expression engine. Presently, in order to try to add support for extraction of matched subexpressions to the engine, I am hacking up the algorithm to add support for tagged DFA functionality, as described e.g. in the paper here -- http://laurikari.net/ville/spire2000-tnfa.pdf

I am curious whether the re2c folks ever considered implementing such an algorithm, and if so what their opinion is on how worthwhile this would be as an improvement.

In the medium-long term, would the re2c project be interested in such functionality (i.e. being able to access the content matched by a regular expression inside the associated code snippet)? If so, it would be good to discuss the best way to prepare a patch in a form that can be used in the re2c codebase, and not just the hacked-up version I'm using in Systemtap.

(I am writing this in advance of being ready with the actual patch, in order to have a good sense of interest levels about the backport while writing it.)

All the best,
      Serhei Makarov