Code that ought to run fast, but can't due to Python limitations.

[Stefan Behnel]

John Nagle wrote:
> Python doesn't have a "switch" or "case" statement, and when
> you need a state machine with many states, that makes for painful,
> slow code.

Cython has a built-in optimisation that maps if-elif-else chains to C's
switch statement if they only test a single int/char variable, even when
you write things like "elif x in [1,5,9,12]". This works in Cython, because
we know that the comparison to a C int/char is side-effect free. It may not
always be side-effect free in Python, so this won't work in general. It
would be perfect for your case, though.

Stefan