pct user docs

[Jonathan Worthington]

Pavlo Korzhyk wrote:
> I play with extensive checks and static analysis at compile-time, and
> probably not belong to Parrot's target group at all ))
>   
Oh, I wouldn't say that; we will, even in Rakudo - a compiler for a very 
dynamic language - need to do a bunch of static analysis, if not for 
error checking then certainly for optimization. The difference probably 
just lies in what analyses we'll be doing.

I expect that doing the analysis over the PAST will be a common way to 
go, and I'm expecting to be able to use some kind of attribute grammar 
approach and be able to write the analyses/transformations in NQP, not 
PIR (we already do have TGE, a attribute grammar engine, implemented). 
Then it's just a case of inserting this extra stage into the compilation 
pipeline (which PCT is designed to allow you to do).

I think the real issue here is that while we have the components to do 
such things, nobody has actually tried to introduce such a stage yet and 
worked out the pitfalls and things we need to fix up to make it simple. 
(Note - if anyone reading actually has done this, I'd love to hear about 
it.) Somebody mentioned they expected it to be fairly easy to do, however...

Jonathan