'isa' keyword

[phil hunt]

On 1 Sep 2005 00:52:54 -0700, talin at acm dot org <viridia at gmail.com> 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).

-- 
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