>
> Earlier on the thread, I made a similar point that it would be nice to
> have a way to filter without the redundant for x in x. Though I can’t think
> of a really good way to express it. But as for filtered for loops:
>
> "for thing in
> (x for x in collection if is_interesting(x))"
>
It's pretty important that comprehensions can express transformations (i.e.
map) along with filters. A lot of the examples and argument for extension
of `filter()` to general loops miss this point.
Yes, `x for x in stuff if pred(x)` looks kinda redundant.
But `transform(x) for x in stuff if pred(x)` really doesn't. And
transformation in my mind is at least as common and at least as
important as filtering.
Happily, I can write this in Python right now:
items = (transform(x) for x in stuff if pred(x))
for item in items:
foo = something_with(item)
bar = something_else(item)
if result(foo, bar): ...
I'm not making a slippery slope argument, I do know one thing is possible
without the other. But if you really want an "entire comprehensions in a
loop statement" we wind up with something like:
for item := transform(x) for x in stuff if pred(x):
foo = something_with(item)
...
Which is obviously a *possible* language, but I'd be -100 on making loop
statements that complicated needlessly. The way we have now is great, and
clear, and already exists. Other spellings are available as well, of
course, such as `if not transform(x): continue`.
--
Keeping medicines from the bloodstreams of the sick; food
from the bellies of the hungry; books from the hands of the
uneducated; technology from the underdeveloped; and putting
advocates of freedom in prisons. Intellectual property is
to the 21st century what the slave trade was to the 16th.
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