phil hunt wrote: > On 1 Sep 2005 00:52:54 -0700, talin at acm dot org <[EMAIL PROTECTED]> wrote: > >>The "isa" operator would of course be overloadable, perhaps by an >>accessor functions called __isa__, which works similarly to >>__contains__. The potential uses for this are not limited to >>isinstance() sugar, however. For example: >> >> if image isa gif: >> elif image isa jpeg: >> elif image isa png: > > > What's wrong with: > > if image.isa(gif): > elif image.isa(jpeg): > elif image.isa(png): > > In short, I see no need to add further complexity to Python's > grammar. > > It could be argued of course, that an OOPL should allow methods to > be sent with a grammar: > > receiver selector argument > > (which is almost what Smalltalk does), but you're not arguing for > that (and I'm not sure it would work with the rest of python's > grammar). > Even if it did it might mangle operator precedence in the same way SmallTalk did, which I always felt was one of the least attractive features" of the language.
I don't think a change to a message-passing paradigm would necessarily benefit Python at this stage. Some people are still under the misapprehension that message-passing is a fundamental of object-oriented programming because of Smalltalk, but they are wrong. The addition of an "isa" operator would be an unnecessary addition of pure syntactic sugar. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list