On Sun, 13 Nov 2005 17:28:59 -0600, [EMAIL PROTECTED] wrote:
[...]
>
>On Sun, Nov 13, 2005 at 09:44:43PM +0000, Bengt Richter wrote:
>> even if expr1 had a __unaryop__ method,
>> expr1 - expr2
>> could not become
>> expr1.__unaryop__(-expr2)
>> unless you forced the issue with
>> expr1 (-expr2)
>
>as opposed to being a function call? I don't think you've solved the
>ambiguity problem yet.
>
Oops ;-) Ok. Parens to control evaluation order in expression sequences could
use the illegal
attribute trailer syntax expr1 .(expr2) so that would be
expr .(-expr)
And the previous MINUS thing would become
MINUS .(a MINUS b)
Not as pretty, but I guess workable when actually needed.
Anyway, to give an idea of possibilities, matrix ops could
be written nicely to operate on lists and lists of lists
(or duck-equiv objects) as an alternative to having e.g.
a matrix class with __POW__(-1) and __MUL__ defined,
and where you might use a matrix class and write
a41 = m44**-1 * m41
you could operate on duck-lists writing something like
a41 = m44 INV MM m41
where (sketching still ;-)
class INV(MatrixOps):
"""postfix matrix inverse operator"""
@classmethod
def __pfunaryop__(cls, m):
# mx inverse here
return cls.inverse(m)
class MM(MatrixOps):
"""binary matrix multiply operator"""
@classmethod
def __binaryop__(cls, left, right):
# mx product here
return cls.product(left, right)
Regards,
Bengt Richter
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