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Pathological Problems in Parsing

Hello LtU!

I have composed an algorithm for a garbage-collected LL-derived parser for extracting parse forests in a dynamic-syntax language. I'm not really sure how to go about calculating the time complexity though, I have no formal training. So far all my tests seem to indicate that the algorithm is O(n^2) in the length of the input in the worst-case and linear in the best case.

Since it has been stated that GLR can take O(n^3) in the worst case i find my result surprising. I have been unable to locate any examples that trigger the O(n^3) behaviour in the GLR though.

So my question is, does do readers of LtU have any examples of really pathological grammars?

By disnesquick at 2011-12-05 09:17 | LtU Forum | 5 comments | other blogs | 7557 reads