A string interning library for Rust, developed as part of the Servo project.
In Cargo.toml:
[dependencies] string_cache = "0.9"
In lib.rs:
extern crate string_cache; use string_cache::DefaultAtom as Atom;
In Cargo.toml:
[package] build = "build.rs" [dependencies] string_cache = "0.9" [build-dependencies] string_cache_codegen = "0.6"
In build.rs:
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:
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:
fn compute_something(input: &foo::FooAtom) -> u32 { match *input { foo_atom!("foo") => 1, foo_atom!("bar") => 2, _ => 3, } }