On 12/25/2012 6:04 PM, anatoly techtonik wrote:
logger.debug(Message(factorial, 2, 15))
With this setup, no if statements are needed in your code, and the expensive computations only occur when required.
That's still two function calls and three assignments per logging call. Too expensive and syntax unwieldy. I think everybody agrees now that for existing CPython implementation there is really no solution for the problem of expensive logging calls vs code clarity. You have to implement optimization workaround at the cost of readability.
Anatoly, do you have some measurements to justify the "too expensive" claim? Also, do you have an actual example of expensive logging? I doubt your real code is logging the factorial of 2**15. What is actually in your debug log that is expensive? It will be much easier to discuss solutions if we are talking about actual problems.
The idea is to fix the interpreter, introducing a "feature block" - execution block that works only if it is enabled. Execution block for logging example below is defined by function name "debug" and braces ().
debug( <block contents> )
debug is an object of 'feature' type, which is only executed/evaluated, if the feature is enabled in a table of features.
This feels both sketchy and strange, and not at all integrated with existing Python semantics. --Ned.