[Python-ideas] Adding "Typed" collections/iterators to Python

[Serhiy Storchaka]

19.12.11 15:52, Nathan Rice написав(ла):
>>> L2 = [X(e) for e in L1]>>  L3 = [Y(e) for e in L2]>>  vs>>  L2 = X(L1) # assuming X has been updated to work in both vector/scalar>>  L3 = Y(L2) # context...>>>  L = ['a', 'bc', ['ada', 'a']]>>  What is len(L)? 3 or [1, 2, 2] or [1, 2, [3, 1]]?>>>>  L2 = [Z(Y(X(e))) for e in L1]>>  vs>>  L2 = Z(Y(X(L1)))>>>>  L2 = [e.X().Y().Z() for e in L1]>>  vs>>  L2 = L1.X().Y().Z() # assuming vectorized versions of member methods>>  #are folded into the collection via the mixin.>>>  What is L.count('a')? 1 or [1, 0, 1] or [1, 0, [2, 1]]?
>
> A fair concern; if the vectorized version of the child method were
> given the same name as the child method, I agree that this could
> result in ambiguity.
>
> There are multiple ways that member methods could be made available on
> the collection, including a proxy attribute, renaming, etc.

len is not method, it is function (although it uses method __len__). 
There are many functions applicable to list and to its elements (in 
particular when members of list are lists).