On Fri, 28 Jan 2005, Clifford Heath wrote:

> Hugh Sasse Staff Elec Eng wrote:
>> According to "Crafting a Compiler" ISBN 0-8053-3201-4 it seems that
>> recursive descent implies LL(1)...
>
> No. LL(1) just means that the recursive descent parser may only consider
> the current unprocessed token. If the lexer allows perusal of two
> unprocessed tokens, your recursive descent parser is LL(2).

Isn't that just re-framing the problem so that all token pairs are
regarded as single entities?  Then at the level of what the parser
processes, it can only take one entity at a time?  Tokenizing
generally lumps things together anyway, so /(\d+)/ rather than
/(?:(\d)+)/, therefore having the lexer peruse two tokens feels
like a special case.
>
Anyway, I hope I haven't misrepresented what the book says.
         Hugh
>