# string-cache
[](https://github.com/servo/string-cache/actions)
[Documentation](https://docs.rs/string_cache/)
A string interning library for Rust, developed as part of the [Servo](https://github.com/servo/servo) project.
## Simple usage
In `Cargo.toml`:
```toml
[dependencies]
string_cache = "0.8"
```
In `lib.rs`:
```rust
extern crate string_cache;
use string_cache::DefaultAtom as Atom;
```
## With static atoms
In `Cargo.toml`:
```toml
[package]
build = "build.rs"
[dependencies]
string_cache = "0.8"
[build-dependencies]
string_cache_codegen = "0.5"
```
In `build.rs`:
```rust
extern crate string_cache_codegen;
use std::env;
use std::path::Path;
fn main() {
string_cache_codegen::AtomType::new("foo::FooAtom", "foo_atom!")
.atoms(&["foo", "bar"])
.write_to_file(&Path::new(&env::var("OUT_DIR").unwrap()).join("foo_atom.rs"))
.unwrap()
}
```
In `lib.rs`:
```rust
extern crate string_cache;
mod foo {
include!(concat!(env!("OUT_DIR"), "/foo_atom.rs"));
}
```
The generated code will define a `FooAtom` type and a `foo_atom!` macro.
The macro can be used in expression or patterns, with strings listed in `build.rs`.
For example:
```rust
fn compute_something(input: &foo::FooAtom) -> u32 {
match *input {
foo_atom!("foo") => 1,
foo_atom!("bar") => 2,
_ => 3,
}
}
```