https://github.com/jfrimmel/partial-array

A rust crate providing a potentially partial-filled array
https://github.com/jfrimmel/partial-array

array collect iterator no-dependencies no-std partial-array rust

Last synced: 2 days ago
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A rust crate providing a potentially partial-filled array

• Host: GitHub
• URL: https://github.com/jfrimmel/partial-array
• Owner: jfrimmel
• License: apache-2.0
• Created: 2021-08-31T11:42:18.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2021-12-12T15:47:04.000Z (about 3 years ago)
• Last Synced: 2025-01-02T16:19:42.489Z (30 days ago)
• Topics: array, collect, iterator, no-dependencies, no-std, partial-array, rust
• Language: Rust
• Homepage: https://crates.io/crates/partial-array
• Size: 51.8 KB
• Stars: 0
• Watchers: 1
• Forks: 1
• Open Issues: 7
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE-APACHE

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README

        
# `partial-array` - potentially partial-filled arrays for `#![no_std]`

[![Crates.io](https://img.shields.io/crates/v/partial-array.svg)](https://crates.io/crates/partial-array)

[![Docs.rs](https://docs.rs/partial-array/badge.svg)](https://docs.rs/partial-array)

This crate provides a central new data type, similar to an [array]: the [`PartialArray`][partialarray].

It is equivalent to an array, but the number of entries might be anywhere from `0` to `N`.

While this has similarities to a `Vec` keep in mind, that a [`PartialArray`][partialarray] does not grow its memory: it always takes up the memory for the fully array (with some additional counter) and it cannot ever hold more than `N` elements.

This means that its memory is _fully static_ and _on the stack_, making it usable from `#![no_std]` crates.

```rust

// some filter function, even numbers as an easy example

let f = |x: &i32| x % 2 == 0;

let array: partial_array::PartialArray = (0..).take(32).filter(f).collect();

```

## Features

This crate is rather simple, but has a few key features, that might enable this crate to be considered:

- zero dependencies

- `#![no_std]` (enabled for embedded targets without dynamic memory)

- only few `unsafe` code, can be audited easily

- open source

- permissive license

## Example usage

This new data type is most likely to be used for collecting iterators into arrays, when then length is not known, but has an upper bound, e.g.:

```rust

use partial_array::PartialArray;

/// Take the first 10 elements of an iterator, that match the condition.

///

/// This can return less than 10 elements if the iterator has fewer than 10

/// items or there are less than 10 matching elements.

fn first_10_matching(iter: I, check: F) -> PartialArray

    where I: IntoIterator,

          F: FnMut(&T) -> bool,

{

    iter.into_iter().filter(check).take(10).collect()

}

```

[array]: https://doc.rust-lang.org/nightly/core/primitive.array.html

[partialarray]: https://docs.rs/partial-array/latest/partial_array/struct.PartialArray.html