feat(corelib): iter::adapters::Filter

[julio4]

Stacked on #7151

Creates an iterator which uses a closure to determine if an element should be yielded.

Given an element the closure must return true or false. The returned iterator will yield only the elements for which the closure returns true.

Example

let a = array![0_u32, 1, 2];

let mut iter = a.into_iter().filter(|x| x > 0);

assert_eq!(iter.next(), Option::Some(1));
assert_eq!(iter.next(), Option::Some(2));
assert_eq!(iter.next(), Option::None);

[reviewable-StarkWare]

This change is 

[orizi]

Reviewed 1 of 4 files at r1, all commit messages.
Reviewable status: 1 of 4 files reviewed, 1 unresolved discussion (waiting on @julio4)

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corelib/src/iter/adapters/filter.cairo line 32 at r1 (raw file):

    fn next(ref self: Filter<I, P>) -> Option<Self::Item> {
        self.iter.find(self.predicate)
    }

Suggestion:

pub impl FilterIterator<
    I,
    P,
    impl TIter: Iterator<I>,
    +core::ops::Fn<P, (TIter::Item,)>[Output: bool],
    +Destruct<I>,
    +Destruct<P>,
    +Destruct<TIter::Item>,
> of Iterator<Filter<I, P>> {
    type Item = TIter::Item;
    fn next(ref self: Filter<I, P>) -> Option<Self::Item> {
        self.iter.find(self.predicate)
    }

[julio4]

Reviewable status: 0 of 4 files reviewed, 1 unresolved discussion (waiting on @orizi)

---

corelib/src/iter/adapters/filter.cairo line 32 at r1 (raw file):

    fn next(ref self: Filter<I, P>) -> Option<Self::Item> {
        self.iter.find(self.predicate)
    }

I'm not sure if it's possible to not copy the predicate closure.

[orizi]

Reviewed 1 of 4 files at r2, all commit messages.
Reviewable status: 1 of 4 files reviewed, 2 unresolved discussions (waiting on @julio4 and @TomerStarkware)

---

corelib/src/iter/adapters/filter.cairo line 32 at r1 (raw file):

Previously, julio4 (Julio) wrote…

I'm not sure if it's possible to not copy the predicate closure.

It is probably ok for this case/
@TomerStarkware ?

---

corelib/src/iter/adapters/filter.cairo line 18 at r2 (raw file):

}

pub impl FilterIterator<

Suggestion:

impl FilterIterator<

[TomerStarkware]

Reviewable status: 1 of 4 files reviewed, 2 unresolved discussions (waiting on @julio4, @orizi, and @TomerStarkware)

---

corelib/src/iter/adapters/filter.cairo line 32 at r1 (raw file):

Previously, orizi wrote…

It is probably ok for this case/
@TomerStarkware ?

self.iter.find(@self.predicate)
should work without +Copy

[julio4]

Reviewable status: 1 of 4 files reviewed, 1 unresolved discussion (waiting on @orizi and @TomerStarkware)

---

corelib/src/iter/adapters/filter.cairo line 32 at r1 (raw file):

Previously, TomerStarkware wrote…

self.iter.find(@self.predicate)
should work without +Copy

True, I didn't know that we could pass closure as snapshot like that. Done!

---

corelib/src/iter/adapters/filter.cairo line 18 at r2 (raw file):

}

pub impl FilterIterator<

Done.

[orizi]

Reviewed 2 of 4 files at r2, 1 of 1 files at r3, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @julio4)

[orizi]

Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @julio4)

---

a discussion (no related file):
@TomerStarkware @gilbens-starkware for 2nd eye.

[TomerStarkware]

Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @julio4)