[Python-Dev] Switch statement (original) (raw)

Fredrik Lundh fredrik at pythonware.com
Wed Jun 21 20:59:03 CEST 2006

Fredrik Lundh wrote:

But in most cases the 'constant' is actually an expression involving a global, often even a global in another module. (E.g. srecompile.py) The compiler will have a hard time proving that this is really a constant, so it won't optimize the code. unless we come up with a way to make it possible to mark an variable as a constant.

such as the primary

 'constant' expr

which simply means that expr will be evaluated at function definition time, rather than at runtime. example usage:

 var = expression
 if var == constant sre.FOO:
     ...
 elif var == constant sre.BAR:
     ...
 elif var in constant (sre.FIE, sre.FUM):
     ...

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