Craig Ringer schrieb:
And then we have iteration ....
(generator expressions, list comprehensions, for loops, ...?) over
(sequences, iterators, generators)
Just sequences and iterators. Generators are functions which return
iterators. Sequences and iterators provide two ways to build
containers.
My use cases:
finite, can be defined by enumeration: use sequence
infinite, must be defined algorithmically: use iterator
generator: neat way to produce an iterator, can also be viewed as
a persistent function call (better than static local variables).
Once defined, sequences and iterators have nearly the same interface.
To have list comprehensions but no equivalent for iterators would
be strange.
I happen to be extremely fond of the flexibility this provides, but one
obvious way to do it there is not.
Development of the language, backward compatibility and obviousness
are diverging goals. You can't satisfy them all at the same time.
And goals provide a direction but are rarely reached. :)
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