Re: Computing FIRST(X) for a left recursive grammar

torbenm@diku.dk (Torben AEgidius Mogensen) wrote:


> You don't want to use sets of strings, you want to use sets of tokens.
> Give each token a number and use bit-vectors. This makes all the set
> operations very fast.


If you frequently iterate over all members currently contained in a set,
you might want to use a sparse set representation a la Briggs' thesis. It
uses more memory, but it's a handy way to avoid some average-case O(N^2)
behavior as the size of the universe grows.


--
John McEnerney (johnmce@texas.net)

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