A possible way to accomplish it would be to use an object graph with an incremental query engine, such as EMF/CDO with Viatra or something similar. You could then put different character sets in connected objects and query only as far as you need to. Andrew Glynn Sent from Mail for Windows 10 From: Thierry Goubier Sent: Tuesday, November 7, 2017 7:17 AM To: Any question about pharo is welcome Subject: Re: [Pharo-users] Binary Decision Diagram Package in Smalltalk Hi Andrew, Steffen, 2017-11-07 13:10 GMT+01:00 Prof. Andrew P. Black <black@cs.pdx.edu>:
On 28 Oct 2017, at 17:37 , Steffen Märcker <merkste@web.de> wrote:
Does that mean the sets/bdd would be constructed mainly at comile time? Anyway, Andrew, feel free to contact me, I might help you with this.
Thanks for the offer, Steffen! The problem is that I need to use SmaCC for my current project, and really do not have a month to take off and re-design the way that it builds its scanner. Iâve talked to Thierry Goubier about, and he doesnât have time either! It would be a fun project, though, and it ought to be fairly separate from other parts of SmaCC. Iâve spent a fair bit of time thinking about how to do it, but donât think that I will be able to actually focus on it. Yes, this is the essence of the issue. There are a few alternatives about it, but none we have the time to pursue.  An alternative approach, which Thierry has suggested, is to make SmaCC work on the UTF-8 representation of the Unicode. Then we could represent character sets as prefix trees. But the core problem would still exist: you canât run an algorithm that repeatedly executes         for all characters in the alphabet do: when there are 2^21 characters in the alphabet! The main issue is that `for all characters`... All the literature on scanner building uses 'for all characters do'. Thierry      Andrew