#string #immutability #stack #fixed-size #thread-safety #no-std

no-std rocstr

An immutable fixed capacity stack based generic copy string

3 unstable releases

0.6.1 Jul 5, 2024
0.6.0 Jul 5, 2024
0.5.1 Jun 28, 2024

#1293 in Data structures

Download history 198/week @ 2024-06-28 254/week @ 2024-07-05 4/week @ 2024-07-12

101 downloads per month

MIT/Apache

56KB
1K SLoC

rocstr

Maintenance: actively-developed Rust: ^1.60 crates.io docs.rs GitHub Actions: Security Audit GitHub Actions: Unit Tests Codecov

RocStr

Overview

Rust OuiCloud Str

An immutable fixed capacity stack based generic copy string.

The RocStr is a string backed by a fixed size array.

It keeps track of its length, and is parameterized by SIZE for the maximum capacity.

SIZE is of type usize but is range limited to u32::MAX; attempting to create RocStr with larger capacity will panic.

Usage

Basic usage

cargo install rocstr

pub struct Customer {
    id: u32,
    first_name: RocStr<64>,
    last_name: RocStr<64>,
}

let alice = Customer {id: 1, first_name: "Alice".into(), last_name: "Adams".into()};
let bob = Customer {id: 2, first_name: "Bob".into(), last_name: "Bennett".into()};

let alice_name = alice.first_name + " " + alice.last_name;
let bob_name = bob.first_name + " " + bob.last_name;

assert_eq!(alice_name, "Alice Adams");
assert_eq!(bob_name, "Bob Bennett");

Motivation

Yet another copy string type for Rust.

But, this one is particularly shaped to ease async programming :

  • it is owned which means no lifetime management, unlike Rust standard &str
  • it implements Copy trait, unlike Rust standard String, which means fast and implicit copy
  • it exposed an immutable API, no interior mutability, which means thread safety

More over, it was designed to cover web full stack programming range, from full featured back-end server to WASM front-end.

Library owned impl Copy immut. API no std no unsafe Note
core::str core immutable string
std::String std string
imstr::ImString use Arc<String> under the hood
smol_str::SmolStr rust-analyzer string
bytestring::ByteString actix string
flexstr::FlexStr
copstr::Str
copystr::sXX old impl before const generic
arraystring::ArrayString old impl before const generic
tinystr::TinyAsciiStr ascii only
arrayvec::ArrayString unfortunately, it uses unsafe
rocstr::RocStr this crate

Use cases

The target use case is web full stack programming :

  • mapping database strings with bound size (char(SIZE), varchar(SIZE), etc…)
  • easing async functional programming (owned, impl Copy, immutability)

Supported Rust Versions

The current MSRV is 1.60.

Safety

This crate uses #![forbid(unsafe_code)] to ensure everything is implemented in 100% Safe Rust.

Crate Features

RocStr is built with these features enabled by default:

  • std enables functionality dependent on the std lib

Optionally, the following dependencies can be enabled:

  • serde enables serde Serialize/Deserialize support
  • postgres enables PostgreSql type support

RocStr supports no_std mode (enabled via default-features = false)

License

RocStr is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT, and COPYRIGHT for details.

Dependencies

~0–700KB
~17K SLoC