I reread his example and have to admit I'm confused: He complains about having written his _own_ vector class - and concatenation and addition had to use both + ?
I've interpreted it as:
If Python had choosen different operators for addition and sequence concatenation, I could have implemented them both in my vector class. As it is, I have to implement one of them using a non-standard operator.
The examples focus too much on numbers - if we use instead
("foo")
we would get a iterable yielding ["foo",] or - as string already supports iteration - ['f', 'o', 'o']. Which one to chose?
What I was hinting at (NOT proposing, I'd hate this) was that integers implement the [] operator. 5 [0] would then return 5, for all practical purposes, it would look like a tuple. String already implements []. Yes, that would lead to really surprising and inconsistent behaviour.
I find this 'creative use of overloading' rather awful. But what the heck, I find list comprehension rather awful.
Well, the number of operators built into the language is limited - and I actually prefer to have the possibility to overload these if I want to. Nobody forces me - I could use
v1.concat(v2)
for two vectors v1, v2 if I wanted to.
My peeve is about having operators added to standard types. This increases the chances that using an object the wrong way leads to a bogus result, not a runtime error. A more common programming error I commit is passing a string where a list ist expected. And then I wonder why later operations work on one-character strings.
Operator overloading is certainly an irregular verb: - I make the usage more intuitive - Yours may lead to misinterpretation - He obfuscates
Daniel -- http://mail.python.org/mailman/listinfo/python-list
