Re: incremental lexing

[Mark Slicker <jamess1 wwnet net>]

On Wed, 25 Apr 2001, Owen Fraser-Green wrote:
> 
> I'm interested in helping all I can. At the moment I'm a little bogged down 
> in another project but I've just sent Tim A. Wagner's paper "Practical 
> Algorithms for Incremental Software Development Environments" to the 
> printer so that should make good bedtime reading :)
>

That is required reading for this project. ;)

> Yes, it's very regrettable that they havn't made any code available. I sent 
> a mail to the head of faculty, Susan Graham but so far havn't received any 
> reply. I read that Ensemble (Harmonia's predecessor) consisted of over 
> 300,000 lines of code so I would guess writing even just the incremental 
> lexing part would be a mamoth task.

Not really. A good deal of incremental lexing is handled by the batch
lexer flex, and the incremental algorithm is pretty easy to follow.
Really, I almost had most of this done and also incremental parsing which 
is similarly handled by the bison program. The parts I considered more
difficult or requiring a lot of work are the grammar tools used for
turning a language specification into a language module used by the
system. Also incremental semantic analysis looks fairly difficult, mainly
because their isn't an easy to follow paper like Tim Wagner's Thesis. And
on top of all of this there is incremental preprocessing required for a
language like C or C++. I had a good idea of how to handle this, but it is
still a bit of work to implement it properly.

Any way, you can see that there is a lot of work to get to point of where
Harmonia is. Working on an alternative is only justified by uncertainy of
a release of Harmonia, or by techincal considerations after seeing a
release of Harmonia. I am somewhat uncertain of release date, if they say
months, it would probably be reasonable to expect a release by the end of
the year. There is always a possiblity of not releasing at all. Another
option for us is just completing the structural analysis part of gpf. I
think this would be quite useful to have, even if the application writer
would have to handle the semantic analysis (if required) him or her
self. And it could probably be completed in a reasonable amount of time.

> 
> Assuming you do decide to resurrect gpf, could you consider moving it to 
> SourceForge to open the development cycle up to others including myself. 
> For that matter, would it be viable to move the whole gIDE project to SF 
> following the demise of the old home page?
> 

I can't comment for gIDE, but I don't know the benifit of moving gpf at
this point. It's more of a general purpose library, so maybe
SourceForge is more appropriate, but if it is completed I expect a
majority of Gnome development tools to use it so this why it might be
justified for the gnome cvs. In either case the development is just as
open, but maybe a little less publicised in the gnome cvs.

Mark