Hans Aberg writes: > At 10:58 -0500 2002/01/20, Anthony DeRobertis wrote: >>I'm beginning to agree with Scott that LALR(1) isn't enough. > > First note that languages are often not themselves LL(1) or LALR(1) even > though such parsers may be used: One can tweak the lexer by say a lookup > table deciding which token to return. Or one can decide that some data is > semantic, and let it be handled via the actions. This data can the be fed > back to alter the lexer.
I'm going to be depending on those facts quite a bit. > > So if you say that the original parser used a recursive decent parser > (probably LL(1) then), I doubt LL(1). > Thus, it may look as though a larger lookahead is needed in a simplistic > analysis. Yes, that's quite true. And I think I unfortunately aided simplistic analysis by my poor choice of examples! > passes Bison. So your example is parsable with one token lookahead LALR. I think it's about time I posted what I have of the grammar. It's 480 lines, so I'll just give a URL: <http://freecard.sourceforge.net/InterpreterExpirement/parser.y> You'll need to find a nice 132-character display to make it readable --- sorry about that. Also, I use 4-character tabs... The parts I was giving examples from are "chunk", "part_descr". "expr" and "factor" are quite important, too.
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