I know that a bottom-up parser is better than a top-down parser because it can accept left-recursive grammar, what can be other reasons that we prefer bottom-up parsing over top-down parsing?
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I know that a bottom-up parser is better than a top-down parser because it can accept left-recursive grammar, what can be other reasons that we prefer bottom-up parsing over top-down parsing?
Theoretically speaking, the LL(k) grammars are always strict subsets of the LR(k) grammars for any k, so deterministic predictive bottom-up parsers can accept a strictly greater set of grammars than than deterministic predictive top-down parsers. This also means that any LL(k) grammar is also LR(k).
Also, a tricky proof shows that any deterministic CFL (a CFL accepted by a deterministic push down automaton) has an LR(1) grammar, which means that LR grammars correspond precisely to those languages that have efficient stack-based parsing algorithms.
That said, if you allow for more general parsing algorithms like Unger’s algorithm, Earley’s algorithm, or the CYK algorithm, then top-down and bottom-up methods exist for parsing arbitrary CFGs. These algorithms can be much slower than the predictive methods, though, so they typically aren’t used for programming languages.
Hope this helps!