[Python-Dev] Switch statement

Sun Jun 25 21:20:34 CEST 2006

Phillip J. Eby wrote:
>> I don't see this as much of a problem, really: we can simply restrict
>> the optimization to well-known data types ("homogenous" switches using
>> integers or strings should cover 99.9% of all practical cases), and then
>> add an opcode that checks uses a separate dispatch object to check if
>> fast dispatch is possible, and place that before an ordinary if/elif
>> sequence.
>> What about switches on types? Things like XML-RPC and JSON want to be able 
> to have a fast switch on an object's type and fall back to slower tests 
> only for non-common cases.

good point (and nice example).
> for t in obtype.__mro__:
> switch t:
> case int: ...; break
> case str: ...; break
> else:
> continue
> else:
> # not a recognized type

but I wonder how confusing the "break inside switch terminates the outer 
loop" pattern would be to a C programmer...
</F>