feat: Single-word Array component

[mmagician]

We eventually want to have double-word arrays & double-word queues. Once we agreed on the structure and where the files live, it's going to be trivial to extend to double-word array. A queue will require an extra storage slot to hold the metadata, though.

Features:

• add a simple wrapper over storage map, s.t. the map keys are [index, 0, 0, 0]
• export procedures set(index: Felt, VALUE: Word) -> OLD_VALUE: Word & get(index: Felt) -> VALUE: Word
• the account component can be built by specifying the underlying storage slot
• tests that show how other account components have an easy interface for operating on the array

Usage:

use.my_array
use.my_second_array # can hold multiple independent arrays within an account

proc test_get
    push.0
    exec.my_array::get
end

[mmagician]

@copilot add change log entry for this PR 2203

[Copilot]

@mmagician I've opened a new pull request, #2204, to work on those changes. Once the pull request is ready, I'll request review from you.

[Copilot]

Pull request overview

This PR introduces a single-word Array account component that provides a simple, reusable array data structure for Miden accounts. The implementation wraps a StorageMap where array indices are mapped to keys of the form [index, 0, 0, 0].

Key changes:

• Added Array struct with methods for creating arrays with initial elements or from slices
• Implemented MASM procedures (get and set) for array access with configurable storage slots
• Added comprehensive unit tests and integration tests demonstrating the component's usage

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/miden-standards/src/account/array.rs	Core implementation of the Array component with constructors, MASM generation, and conversion to AccountComponent
crates/miden-standards/asm/account_components/array.masm	MASM template defining get and set procedures for array operations
crates/miden-standards/src/account/mod.rs	Adds array module to the account components public API
crates/miden-testing/src/kernel_tests/tx/test_array.rs	Integration test verifying get/set operations work correctly in transaction context
crates/miden-testing/src/kernel_tests/tx/mod.rs	Includes the new test module
CHANGELOG.md	Documents the addition of the Array component

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

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[partylikeits1983]

Looks great! This is a great feature!

When reviewing the implementation, it reminded me of this issue for KEY => vec![] issue I opened: #2085

[bobbinth]

Question: why make this a component rather than just a utility? That is, we could provide the storage slot name as a parameter to get/set procedures and it would work similar to how storage slots/maps work.

[PhilippGackstatter]

I agree this would be preferable. One consequence of "templating" is that the Array account component as it is now would not be detectable in an AccountInterface because it doesn't have a stable MAST root. Not sure if it's important for this component, but whenever possible, I think we should avoid "templating".