predictive parsing and non-recursive predictive parsing

usually covered. But there is a less-known, elegant recursive
formulation for LR parsers as well. Google "recursive LR parser" for
a few papers.

Is this what is refered to as Recursive Ascent ?

Aaron

Is this what is refered to as Recursive Ascent ?

It is indeed.
>
>1) How does it work as I cannot remember, it was used in Philip's Elegant
>Compiler compiler infrastructure, which I looked at some eight years ago.
>Would you please give a description of how it works for those who don't
>know.
>
Basically, you use the call stack as a replacement of the explicit
stack. A shift is a call and a reduce is a return (through several
stack levels).
>
A reasonably good account can be found in "The Essense of LR Parsing"
by Sperber and Thiemann (PEPM'95, ACM Press). It includes several
different implementations in Scheme and a description of how you can
use partial evaluation to generate specialised parsers from the
general parser.

Thanks.

>2) Is it limited to LR(1) lookahead wise ?
>
No.

This is very interesting. So you could implement lookahead before
doing the shift as a "guard". So you could get a very fast LR(k)
parser using this technique, although there is the problem of error
recovery which a no recursive table driven parser does much easier.

Interesting diversion :)

Aaron