parse-time optimizations
jcm
grumble at usa.net
Thu May 31 17:25:24 EDT 2001
Roeland Rengelink <r.b.rigilink at chello.nl> wrote:
> jcm> I didn't realize this was possible in Python. Can you give an
> jcm> example of how a new, right-associative addition operator could
> jcm> be defined?
> well, more asocial than associative, but:
> class X:
> def __add__(self, other):
> print 'Hi', other
> return X()
> x = X()
> y = x+1+2+3
> print y
> gives:
> Hi 1
> Hi 2
> Hi 3
> <__main__.X instance at 0x80cefa4>
> and shouldn't give
> Hi 6
> <__main__.X instance at 0x80cefa4>
Sure, this was covered already--plus is left-associative. Another
poster implied that in Python you can redefine plus so that it is
right-associative for a custom type. Or maybe I misinterpreted him.
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