#str #string #split

nightly str_splitter

Experiment using a combinator API for flexible string splitting

2 releases

0.1.1 Jan 21, 2023
0.1.0 Jan 21, 2023

#18 in #split

MIT license


This crate aims to prevent the combinatorial explosion of str splitting APIs.

The explosions comes from the combinations of the following:

  • reversed (rsplit, rsplit_once, rsplit_terminator, rsplitn)
  • inclusive (split_inclusive)
  • terminated (split_terminator, rsplit_terminator)
  • limited (splitn, rsplitn)
  • once (split_once, rsplit_once)

As you can see, various combinations are currently missing (not exhaustive):

  • inclusive + reversed
  • inclusive + limited
  • inclusive + once
  • inclusive + reversed + limited
  • inclusive + reversed + once

Plus, it may be useful to have right- or left-inclusive versions.

This could quickly balloon the API surface of str which is not ideal.

Instead, this crate implements a kind of builder API. It does this two different ways:

  • using const generic parameters
  • using struct combinators

Both have almost identical APIs. Usage looks like this:

use str_splitter::combinators::SplitExt;
// OR
// use str_splitter::const_generics::SplitExt;

// `split`
let v: Vec<&str> = "lionXXtigerXleopard".splitter('X').collect();
assert_eq!(v, ["lion", "", "tiger", "leopard"]);

// `splitn`
let v: Vec<&str> = "Mary had a little lambda".splitter(' ').with_limit(3).collect();
assert_eq!(v, ["Mary", "had", "a little lambda"]);

// `rsplitn`
let v: Vec<&str> = "lion::tiger::leopard".splitter("::").to_reversed().with_limit(2).collect();
assert_eq!(v, ["leopard", "lion::tiger"]);

// `rsplit_terminator`
let v: Vec<&str> = "A.B.".splitter('.').to_terminated().to_reversed().collect();
assert_eq!(v, ["B", "A"]);

// `rsplit_inclusive_once` if it existed
assert_eq!("cfg=foo=bar".splitter('=').to_inclusive().to_reversed().once(), Some(("cfg=foo", "=bar")));

The idea is that the struct returned by the existing split method would add the various modifier methods that Splitter has in this library.

This crate relies on the unstable Pattern trait, so requires nightly Rust.

No runtime deps