Peter N Lewis wrote:
However, LALR(1) is not the last word in parser generator technology. Recent versions of Bison support so-called GLR parsers (also known as Tomita parsers) which seem capable of resolving all of these conflicts.
((To me, that's the main advantage of generated parsers. Leaving efficiency etc. aside (which doesn't seem to play a major role, anyway),
Are there going to be performance penalties? Currently, GPC is many times slower than CW (probably a factor of 10 to 50 times slower, I haven't measured it), so it certainly would be undesirable to slow it down!
Did anyone suggest to slow it down?
That said, I imagine not much work has been done in to finding where the bottle necks are - has anyone done much in the way of profiling?
Have you? Otherwise, starting such a discussion is somewhere between pointless and FUD ...
FTR, (a) IME most time is spent in code generation, even without optimizing, (b) AFAIK GLR parsers behave the same as LALR(1) in the cases the latter can handle, so the difference is only in the other cases between not being able to parse it at all and parsing it with perhaps a little more effort, and I don't see how RD parsers would do with essentially less effort.
Frank