4 ms·
LL vs. LR vs. GLR
- cousin_it 18y agoA great example of the power of simple explanations. I wish more of math and CS were taught this way. Right now those areas are overflowing with complex-sounding simple ideas.
- eru 18y agoMy anecdotal evidence tells me otherwise. At least in math. The professors presented the material as simple as possible, but not simpler.
- scott_s 18y agoThe what can be conceptually simple, but the how is not. The justifications for how we know that you can generate a parser for any LR grammar, and what exactly that parser will act like, is more involved.
- newt0311 18y agoSome problems: LR parsers are usually more general than LL parsers. That is because building up the context that the author refers to actually takes up more information that not having a context at all. Once again read the dragon book and consult its section on the classes of language grammar LL and LR parsers can work with. However, error recovery in LR parsers is much more difficult and it is a rare human who can write an LR parser.
- tptacek 18y agoWow. I've written LL (handwritten recursive descent) and LR, and worked with GLR generators, and apparently I didn't really understand why any of them worked that way. This guy is amazing.