feat: Storable

[RoeeGross]

Note

Adds compact storage casting utilities and tests.

• Introduces Castable160 (tuple (u128, u32)) and Castable64 (u64) traits with encode/decode
• Implements for unsigned primitives, signed integers via offset mapping, and EthAddress (160-bit)
• Validates round-trip and boundary behavior in new tests, including a panic on non-zero high bits

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[remollemo]

@remollemo reviewed 1 file and made 7 comments.
Reviewable status: 1 of 3 files reviewed, 7 unresolved discussions (waiting on @RoeeGross).

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packages/utils/src/storage/tests/test_utils.cairo line 43 at r1 (raw file):

    let packed = Storable160::encode(val);
    let unpacked: i128 = Storable160::decode(packed);
    assert(val == unpacked, 'i128 mismatch');

why not add also here +/-max values?

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packages/utils/src/storage/tests/test_utils.cairo line 48 at r1 (raw file):

#[test]
fn test_eth_address_storable() {
    let val: EthAddress = 123.try_into().unwrap();

please use a full value for this.
e.g.
0xDb6368868e71eE8D4637954ed51afaEe34c711D3 // just a random one.

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packages/utils/src/storage/utils.cairo line 75 at r1 (raw file):

///   decode(encode(v)) == v
/// - If the type implements `Default` or `Zero`, it is preferred that:
///   encode(default or zero) == (0, 0)

why isn't it a must that it'd be so?

Code quote:

/// - If the type implements `Default` or `Zero`, it is preferred that:
///   encode(default or zero) == (0, 0)

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packages/utils/src/storage/utils.cairo line 76 at r1 (raw file):

/// - If the type implements `Default` or `Zero`, it is preferred that:
///   encode(default or zero) == (0, 0)
pub trait Storable160<V> {

I think Castablexxx is a better name pattern than Storablexxx
as we are not talking about storage, but about into-ability (Intoable would be ok to, but it's confusing as it's too much not a word).

i can live with Storable, nontheless

Code quote:

 Storable1

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packages/utils/src/storage/utils.cairo line 77 at r1 (raw file):

///   encode(default or zero) == (0, 0)
pub trait Storable160<V> {
    /// Convert a value into its 160-bit storage representation `(low, high)`.

why you add the word storage here? woudn't
the wording w/o that word be more accurate?

Suggestion:

/// Convert a value into its 160-bit representation `(low, high)`.

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packages/utils/src/storage/utils.cairo line 84 at r1 (raw file):

}

pub impl PrimitiveStorable160<T, +Into<T, u128>, +TryInto<u128, T>, +Drop<T>> of Storable160<T> {

is this a sub generic for all the u128 castable?
a small comment would be helpful

Code quote:

pub impl PrimitiveStorable160<T, +Into<T, u128>, +TryInto<u128, T>, +Drop<T>> of Storable160<T> {

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packages/utils/src/storage/utils.cairo line 102 at r1 (raw file):

impl I8Offset of SignedIntegerOffset<i8> {
    fn offset() -> felt252 {
        128 // 2^7

2 ^ 7 = 5
these comments are confusing, as in cairo ^ is xor, please use ** for exp

Suggestion:

 2**7

[remollemo]

@remollemo reviewed 2 files and all commit messages.
Reviewable status: all files reviewed, 7 unresolved discussions (waiting on @RoeeGross).

[RoeeGross]

@RoeeGross resolved 6 discussions.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @RoeeGross).

[RoeeGross]

@RoeeGross resolved 1 discussion.
Reviewable status: 1 of 3 files reviewed, all discussions resolved (waiting on @remollemo).

[RoeeGross]

@RoeeGross reviewed 3 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @RoeeGross).

[remollemo]

@remollemo reviewed 2 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved.