| lib.rs |
Rust-PHF is a library to generate efficient lookup tables at compile time using
[perfect hash functions](http://en.wikipedia.org/wiki/Perfect_hash_function).
It currently uses the
[CHD algorithm](http://cmph.sourceforge.net/papers/esa09.pdf) and can generate
a 100,000 entry map in roughly .4 seconds.
MSRV (minimum supported rust version) is Rust 1.60.
## Usage
PHF data structures can be constructed via either the procedural
macros in the `phf_macros` crate or code generation supported by the
`phf_codegen` crate. If you prefer macros, you can easily use them by
enabling the `macros` feature of the `phf` crate, like:
```toml
[dependencies]
phf = { version = "0.11", features = ["macros"] }
```
To compile the `phf` crate with a dependency on
libcore instead of libstd, enabling use in environments where libstd
will not work, set `default-features = false` for the dependency:
```toml
[dependencies]
# to use `phf` in `no_std` environments
phf = { version = "0.11", default-features = false }
```
## Example (with the `macros` feature enabled)
```rust
use phf::phf_map;
#[derive(Clone)]
pub enum Keyword {
Loop,
Continue,
Break,
Fn,
Extern,
}
static KEYWORDS: phf::Map<&'static str, Keyword> = phf_map! {
"loop" => Keyword::Loop,
"continue" => Keyword::Continue,
"break" => Keyword::Break,
"fn" => Keyword::Fn,
"extern" => Keyword::Extern,
};
pub fn parse_keyword(keyword: &str) -> Option<Keyword> {
KEYWORDS.get(keyword).cloned()
}
```
Alternatively, you can use the [`phf_codegen`] crate to generate PHF datatypes
in a build script.
[`phf_codegen`]: https://docs.rs/phf_codegen
## Note
Currently, the macro syntax has some limitations and may not
work as you want. See [#183] or [#196] for example.
[#183]: https://github.com/rust-phf/rust-phf/issues/183
[#196]: https://github.com/rust-phf/rust-phf/issues/196 |
4082 |
| map.rs |
An immutable map constructed at compile time. |
7511 |
| ordered_map.rs |
An order-preserving immutable map constructed at compile time. |
7835 |
| ordered_set.rs |
An order-preserving immutable set constructed at compile time. |
4275 |
| set.rs |
An immutable set constructed at compile time. |
3436 |