[Python-Dev] Simple Switch statement
Phillip J. Eby
pje at telecommunity.com
Sun Jun 25 03:45:14 CEST 2006
At 05:30 PM 6/24/2006 -0700, Raymond Hettinger wrote:
> > I would like to be able to use switches on types, enumerations, and the
>Be careful about wanting everything and getting nothing.
>My proposal is the simplest thing that gets the job done for key use cases
>in real code.
It's ignoring at least symbolic constants and types -- which are certainly
"key use cases found in real code".
Besides which, this is Python. We don't select a bunch of built-in types
and say "these are the only types that work". Instead, we have protocols
(like __hash__ and __eq__) that any object may implement.
If you don't want expressions to be implicitly lifted to function
definition time, you'd probably be better off arguing to require the use of
explicit 'static' for non-literal case expressions.
(Your reverse mapping, by the way, is a non-starter -- it makes the code
considerably more verbose and less obvious than a switch statement, even if
every 'case' has to be decorated with 'static'.)
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