ternary operator

David LeBlanc whisper at oz.net
Sat Feb 8 00:11:54 CET 2003


> -----Original Message-----
> From: python-list-admin at python.org
> [mailto:python-list-admin at python.org]On Behalf Of Andrew Koenig
> Sent: Friday, February 07, 2003 14:29
> To: whisper at oz.net
> Cc: python-list at python.org
> Subject: Re: ternary operator
> 
> 
> David> I think you missed the point twice: it's not about indexing,
> David> it's about calling a function whose side effects you depend on
> David> (always) in a component of an expression that might not get
> David> evaluated.
> 
> I didn't miss that point.
> 
> I think there are two cases that are often confused with each other:
> 
>   1) Calling a function with side effects that you depend on;
> 
>   2) Using one expression to guard another--that is, evaluating
>      one expression to determine whether another is meaningful
>      before evaluating it.
> 
> In general, I think that the first case makes programs harder to
> follow, and the second case makes them easier.  Of course, there
> will always be exceptions, but I think this is true in general.
> 
> The difference is that in case (1), the side effects happen somewhere
> else (otherwise they wouldn't be side effects), whereas in case 2,
> the parts of the computation contribute to the results of the expression
> and nothing else.
> 

D'accord! (Oops, sorry, we don't like the French right now - I agree! ;) )

Dave LeBlanc
Seattle, WA USA





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