Crate array_util

no_std array helpers available without nightly.

Description

Many useful array and slice methods are currently gated by nightly features, though their general functionality and interface is essentially stable. As such this crate provides stable alternatives to the following features, often the same underlying implementation as the current nightly version:

• array_try_from_fn
• array_try_map
• array_chunks
• slice_as_chunks
• slice_flatten

Usage

Users can either import an Ext trait (SliceExt, ArrayExt, or SliceOfArrayExt) traits to bring in the desired methods, or use the bare functions. Note that trait methods have the _ext suffix to avoid collision with the core library methods.

use array_util::ArrayExt;

let a = ["1", "2", "3"];
let b = a.try_map_ext(|v| v.parse::<u32>()).unwrap().map(|v| v + 1);
assert_eq!(b, [2, 3, 4]);

let a = ["1", "2a", "3"];
let b = a.try_map_ext(|v| v.parse::<u32>());
assert!(b.is_err());

let a = ["1", "2", "3"];
let b = array_util::try_map(a, |v| v.parse::<u32>()).unwrap().map(|v| v + 1);
assert_eq!(b, [2, 3, 4]);

let a = ["1", "2a", "3"];
let b = array_util::try_map(a, |v| v.parse::<u32>());
assert!(b.is_err());

Limitations

These functions aren’t stabilized because they rely on undecided behaviors. For example, “should compile-time errors be generated for 0 length arrays?” or “What should the associated types and traits of Try be?”. As these questions remain unresolved, reliance on the particular answers this crate has chosen in it’s implementation may make porting to the eventual stabilized version more painful. If you’re just calling functions, you’ll probably be fine, but try to avoid using the Ext traits as bounds.

Structs

• ArrayChunks
  An iterator over a slice in (non-overlapping) chunks (N elements at a time), starting at the beginning of the slice.
• ArrayChunksMut
  An iterator over a slice in (non-overlapping) mutable chunks (N elements at a time), starting at the beginning of the slice.

Traits

• ArrayExt
  A helper extension trait for arrays
• SliceExt
  A helper extension trait for slices
• SliceOfArrayExt
  A helper extension trait for slices of arrays

Functions

• array_chunks
  Returns an iterator over N elements of the slice at a time, starting at the beginning of the slice.
• array_chunks_mut
  Returns an iterator over N elements of the slice at a time, starting at the beginning of the slice.
• as_chunks
  Splits the slice into a slice of N-element arrays, starting at the beginning of the slice, and a remainder slice with length strictly less than N.
• as_chunks_mut
  Splits the slice into a slice of N-element arrays, starting at the beginning of the slice, and a remainder slice with length strictly less than N.
• as_chunks_unchecked^⚠
  Splits the slice into a slice of N-element arrays, assuming that there’s no remainder.
• as_chunks_unchecked_mut^⚠
  Splits the slice into a slice of N-element arrays, assuming that there’s no remainder.
• as_rchunks
  Splits the slice into a slice of N-element arrays, starting at the end of the slice, and a remainder slice with length strictly less than N.
• as_rchunks_mut
  Splits the slice into a slice of N-element arrays, starting at the end of the slice, and a remainder slice with length strictly less than N.
• flatten
  Takes a &[[T; N]], and flattens it to a &[T].
• flatten_mut
  Takes a &mut [[T; N]], and flattens it to a &mut [T].
• try_from_fn
  Creates an array [T; N] where each fallible array element T is returned by the cb call. Unlike from_fn, where the element creation can’t fail, this version will return an error if any element creation was unsuccessful.
• try_map
  A fallible function f applied to each element on array self in order to return an array the same size as self or the first error encountered.