slyce

Slyce implements a python-like slicer for rust.

Indices can be addressed as absolute positions or relative to the end of the array (Tail). Out of bound indices are ignored.

Slice indices are represented with an enum that wraps the full usize range, but also captures the possibility of a "negative" or "backward" index. This crate provides a few implementations of From<T> for Index for common types, so you can pass numbers and options instead of Index (just call .into()).

Example

use slyce::{Slice, Index};
let v = vec![10,20,30,40,50];
let render = |s: Slice| format!("{:?}", s.apply(&v).collect::<Vec<_>>());

let start: isize = -3;
let s = slyce::Slice{start: start.into(), end: Index::Default, step: None};
assert_eq!(render(s), "[30, 40, 50]");

let s = slyce::Slice{start: Index::Tail(3), end: Index::Default, step: None};
assert_eq!(render(s), "[30, 40, 50]");

let end: Option<isize> = None;
let s = slyce::Slice{start: Index::Tail(3), end: end.into(), step: None};
assert_eq!(render(s), "[30, 40, 50]");

let s = slyce::Slice{start: Index::Tail(3), end: Index::Default, step: Some(-1)};
assert_eq!(render(s), "[30, 20, 10]");

let s = slyce::Slice{start: Index::Head(4), end: Index::Head(0), step: Some(-1)};
assert_eq!(render(s), "[50, 40, 30, 20]");

let s = slyce::Slice{start: Index::Default, end: Index::Head(0), step: Some(-1)};
assert_eq!(render(s), "[50, 40, 30, 20]");

let s = slyce::Slice{start: Index::Tail(1000), end: 2000.into(), step: None};
assert_eq!(render(s), "[10, 20, 30, 40, 50]");

Development

Fuzzing

Install cargo-fuzz:

$ cargo install cargo-fuzz

Run the fuzzer:

$ cargo +nightly fuzz run fuzz_target_1

Documentation

Slyce is documented using rust documentation comments throughout the source files. The README.md is generated by combining the README.tpl file and the rustdoc comments:

$ cargo install cargo-readme
$ ./scripts/gen-readme.sh

The README.tpl file should contain the documentation about the project governance and tooling, while the inline rustdoc comments should document what the project actually does from the POV of a user consuming the crate(s).

License

BSD-2-Clause