BCS wrote: > Hello Ellery, > >> BCS wrote: >> >>> 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) >>> >> Small world :) >> >> For some reason, my professor seems to be skipping LR parsing. >> > > If mine did that I'd shoot him (a scorching e-mail :) > >
It's probably because he can't make us write a LALR parser by hand.