feat(corelib): ByteArrayIterator

[julio4]

Close #6817

Implement iter::IntoIterator<ByteArray> following ByteArrayTrait::len() and ByteArrayTrait::at() -> Option<u8>

Example

let ba: ByteArray = "hello";
let expected = array!['h', 'e', 'l', 'l', 'o'];
let mut i = 0;
for c in ba {
    assert_eq!(c, *expected[i]);
    i += 1;
}

[reviewable-StarkWare]

This change is 

[orizi]

Reviewable status: 0 of 4 files reviewed, 3 unresolved discussions (waiting on @julio4)

---

corelib/src/ops.cairo line 14 at r1 (raw file):

#[allow(unused_imports)]
use range::RangeOp;
pub use range::{Range, RangeTrait};

making it public sounds more sensible for me.

Suggestion:

mod range;
// `RangeOp` is used internally by the compiler.
#[allow(unused_imports)]
use range::RangeOp;
pub use range::{Range, RangeTrait, RangeIterator};

---

corelib/src/byte_array.cairo line 498 at r1 (raw file):

pub struct ByteArrayIter {
    ba: ByteArray,
    alive: crate::ops::range::RangeIterator<usize>,

alive?

Code quote:

    alive: crate::ops::range::RangeIterator<usize>,

---

corelib/src/byte_array.cairo line 498 at r1 (raw file):

pub struct ByteArrayIter {
    ba: ByteArray,
    alive: crate::ops::range::RangeIterator<usize>,

add a todo to do an actual efficient implementation (as something more intrusive would obviously be more efficient)

Code quote:

pub struct ByteArrayIter {
    ba: ByteArray,
    alive: crate::ops::range::RangeIterator<usize>,

[julio4]

corelib/src/byte_array.cairo line 498 at r1 (raw file):

Previously, orizi wrote…

alive?

Alive kind of represent the elements that are not yet yielded, so the range of active/valid elements in the iterator lifecycle, with the previous ones being "dead"/consumed.
Maybe there's a better name, feel free to make suggestion.

[orizi]

Reviewed all commit messages.
Reviewable status: 0 of 4 files reviewed, 3 unresolved discussions (waiting on @julio4)

---

corelib/src/byte_array.cairo line 498 at r1 (raw file):

Previously, julio4 (Julio) wrote…

Alive kind of represent the elements that are not yet yielded, so the range of active/valid elements in the iterator lifecycle, with the previous ones being "dead"/consumed.
Maybe there's a better name, feel free to make suggestion.

even current_index sounds better in my mind.

[julio4]

Reviewable status: 0 of 4 files reviewed, 3 unresolved discussions (waiting on @orizi)

---

corelib/src/byte_array.cairo line 498 at r1 (raw file):

Previously, orizi wrote…

add a todo to do an actual efficient implementation (as something more intrusive would obviously be more efficient)

Done.

---

corelib/src/byte_array.cairo line 498 at r1 (raw file):

Previously, orizi wrote…

even current_index sounds better in my mind.

Done.

---

corelib/src/ops.cairo line 14 at r1 (raw file):

Previously, orizi wrote…

making it public sounds more sensible for me.

Done.

[orizi]

Reviewed all commit messages.
Reviewable status: 0 of 4 files reviewed, 2 unresolved discussions (waiting on @julio4)

---

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

---

corelib/src/test/byte_array_test.cairo line 495 at r2 (raw file):

        i += 1;
    };
    assert_eq!(iter.next(), Option::None);

feels more direct for me.

Suggestion:

    let ba: ByteArray = "hello";
    let mut iter = ba.into_iter();
    assert_eq!(iter.next(), Option::Some('h');
    assert_eq!(iter.next(), Option::Some('e');
    assert_eq!(iter.next(), Option::Some('l');
    assert_eq!(iter.next(), Option::Some('l');
    assert_eq!(iter.next(), Option::Some('o');
    assert_eq!(iter.next(), Option::None);

[julio4]

Reviewable status: 0 of 4 files reviewed, 2 unresolved discussions (waiting on @orizi)

---

corelib/src/test/byte_array_test.cairo line 495 at r2 (raw file):

Previously, orizi wrote…

feels more direct for me.

Done.

[orizi]

Reviewed all commit messages.
Reviewable status: 0 of 4 files reviewed, 2 unresolved discussions (waiting on @julio4)

---

corelib/src/test/language_features/for_test.cairo line 78 at r3 (raw file):

        i += 1;
    }
}

no need for this test - this is for for tests - not for iterators.

Code quote:

#[test]
fn test_for_loop_ba() {
    let ba: ByteArray = "hello";
    let expected = array!['h', 'e', 'l', 'l', 'o'];
    let mut i = 0;
    for c in ba {
        assert_eq!(c, *expected[i]);
        i += 1;
    }
}

[julio4]

Reviewable status: 0 of 4 files reviewed, 2 unresolved discussions (waiting on @orizi)

---

corelib/src/test/language_features/for_test.cairo line 78 at r3 (raw file):

Previously, orizi wrote…

no need for this test - this is for for tests - not for iterators.

Done.

[gilbens-starkware]

Reviewable status: 0 of 4 files reviewed, 3 unresolved discussions (waiting on @julio4 and @orizi)

---

corelib/src/byte_array.cairo line 505 at r3 (raw file):

    type Item = u8;
    /// Advances the iterator and returns the next value. Returns `Option::None` when iteration is
    /// finished.

The trait function is documented, and this isn't adding anything specific to the impl

[orizi]

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

[julio4]

Reviewable status: 2 of 4 files reviewed, 2 unresolved discussions (waiting on @gilbens-starkware and @orizi)

---

corelib/src/byte_array.cairo line 505 at r3 (raw file):

Previously, gilbens-starkware (Gil Ben-Shachar) wrote…

The trait function is documented, and this isn't adding anything specific to the impl

Done.

[orizi]

Reviewed 1 of 1 files at r4, 1 of 1 files at r5, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @gilbens-starkware)

[gilbens-starkware]

Reviewed 1 of 2 files at r2, 1 of 1 files at r3, 1 of 1 files at r4, 1 of 1 files at r5, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @julio4)