[Python-Dev] Simple Switch statement

Sun Jun 25 20:13:37 CEST 2006

> Sorry, no go. You can say "supports key use cases found in real code"
> as often as you like,

Those were not empty words. I provided two non-trivial worked-out examples 
taken from sre_constants.py and opcode.py. Nick provided a third example from 
decimal.py. In all three cases, the proposal was applied effortlessly resulting 
in improved readability and speed. I hope you hold other proposals to the same 
standard.
> If you want to provide a solution for the constantification issue,
> let's discuss that first and then come back here.

No thanks. That is its own can of worms. The obvious solutions (like const 
declarations, macros, or a syntax to force compile-time expression evaluation) 
are unlikely to sit well because they run afoul Python's deeply ingrained 
dynamism.
The switch-case construct in C uses constant cases but depends on macros to make 
the constants symbolic. Is that where we want to go with Python? If so, that 
is most likely a Py3k discussion.
In contrast, the proposed simple switch statement is something we could have 
right away. I will likely write-up a PEP and get a sample implementation so we 
can discuss something concrete at EuroPython.
Raymond