On 6/22/06, Roger Miller <[EMAIL PROTECTED]> wrote: > Part of the readability advantage of a switch over an if/elif chain is > the semantic parallelism, which would make me question mixing different > tests in the same switch. What if the operator moved into the switch > header? > > switch x ==: > case 1: foo(x) > case 2, 3: bar(x) > > switch x in: > case (1, 3, 5): do_odd(x) > case (2, 4, 6): do_even(x) > > "switch x:" could be equivalent to "switch x ==:", for the common case.
That's difficult (I mean impossible) for Python's parser, since x == is also the legal start of an expression. > I've also been wondering whether the 'case' keyword is really necessary? > Would any ambiguities or other parsing problems arise if you wrote: > > switch x: > 1: foo(x) > 2: bar(x) > > It is debatable whether this is more or less readable, but it seemed > like an interesting question for the language lawyers. That's no problem for the parser, as long as the expressions are indented. ABC did this. But I think I like an explicit case keyword better; it gives a better error message if the indentation is forgotten. -- --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
