On 6/21/06, Phillip J. Eby <[EMAIL PROTECTED]> wrote: > At 03:38 AM 6/21/2006 -0500, Ka-Ping Yee wrote: > >On Wed, 21 Jun 2006, Phillip J. Eby wrote: > > > Well, EIBTI and all that: > > > > > > switch x: > > > case == 1: foo(x) > > > case in S: bar(x) > > > > > > It even lines up nicely. :) > > > >Hmm, this is rather nice. I can imagine possible use cases for > > > > switch x: > > case > 3: foo(x) > > case is y: spam(x) > > case == z: eggs(x) > > > >An interesting use case for which this offers no corresponding > >syntax is > > > > case instanceof ClassA: ham(x) > > Actually, I was assuming that any other operator besides == and 'in' would > be relegated to an if-elif chain in the default case, although it's almost > possible to do that automatically, I suppose.
I've been thinking about generalization to other operators too, but decided that it would be a mistake. It would be quite clumsy to explain the exact semantics: if all operators are "==" or "in" an efficient hash table gets pre-constructed at function definition time, otherwise, um..., what exactly? (Note how I've switched to the switch-for-efficiency camp, since it seems better to have clear semantics and a clear reason for the syntax to be different from if/elif chains.) -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
