[beza1e1]

Why would that be a good idea? What advantage would a just-in-time parser generator have that a static parser generator does not?

[haberman]

Fast parsing from any language (even slow languages like Ruby) without having to compile and link generated C code for every grammar into the interpreter.

With this approach, you could have a C extension that could load any grammar at runtime and parse it extremely fast.

C/Assembly code is orders of magnitude faster at parsing than generating eg. Ruby that does the parsing.