dmd support for IDEs and the D tool chain

[BCS]

Hello Ellery,

> Do LALR parsers care about arbitrary
> lookahead? LL(k) parsers do.
> 

LALR needs to be able to unambiguously determine all the /completed/ productions 
to the left of each point by looking at nothing beyond the next token to 
the right. This might not be conservative enough, but I seem to remember 
that most parser corner cases don't crop up in practice.

In general LL needs to known exactly what productions are "in process" where 
are LR needs to, at each level, have a finite set of options and only needs 
things to become unambiguous before it finishes a production.

(BTW I'm taking (but haven't yet finished) a compilers class so I might be 
missing something)