phf/
lib.rs

1//! Rust-PHF is a library to generate efficient lookup tables at compile time using
2//! [perfect hash functions](http://en.wikipedia.org/wiki/Perfect_hash_function).
3//!
4//! It currently uses the
5//! [CHD algorithm](http://cmph.sourceforge.net/papers/esa09.pdf) and can generate
6//! a 100,000 entry map in roughly .4 seconds.
7//!
8//! MSRV (minimum supported rust version) is Rust 1.61.
9//!
10//! ## Usage
11//!
12//! PHF data structures can be constructed via either the procedural
13//! macros in the `phf_macros` crate or code generation supported by the
14//! `phf_codegen` crate. If you prefer macros, you can easily use them by
15//! enabling the `macros` feature of the `phf` crate, like:
16//!
17//!```toml
18//! [dependencies]
19//! phf = { version = "0.12", features = ["macros"] }
20//! ```
21//!
22//! To compile the `phf` crate with a dependency on
23//! libcore instead of libstd, enabling use in environments where libstd
24//! will not work, set `default-features = false` for the dependency:
25//!
26//! ```toml
27//! [dependencies]
28//! # to use `phf` in `no_std` environments
29//! phf = { version = "0.12", default-features = false }
30//! ```
31//!
32//! ## Example (with the `macros` feature enabled)
33//!
34//! ```rust
35//! use phf::phf_map;
36//!
37//! #[derive(Clone)]
38//! pub enum Keyword {
39//!     Loop,
40//!     Continue,
41//!     Break,
42//!     Fn,
43//!     Extern,
44//! }
45//!
46//! static KEYWORDS: phf::Map<&'static str, Keyword> = phf_map! {
47//!     "loop" => Keyword::Loop,
48//!     "continue" => Keyword::Continue,
49//!     "break" => Keyword::Break,
50//!     "fn" => Keyword::Fn,
51//!     "extern" => Keyword::Extern,
52//! };
53//!
54//! pub fn parse_keyword(keyword: &str) -> Option<Keyword> {
55//!     KEYWORDS.get(keyword).cloned()
56//! }
57//! ```
58//!
59//! Alternatively, you can use the [`phf_codegen`] crate to generate PHF datatypes
60//! in a build script.
61//!
62//! [`phf_codegen`]: https://docs.rs/phf_codegen
63//!
64//! ## Note
65//!
66//! Currently, the macro syntax has some limitations and may not
67//! work as you want. See [#183] or [#196] for example.
68//!
69//! [#183]: https://github.com/rust-phf/rust-phf/issues/183
70//! [#196]: https://github.com/rust-phf/rust-phf/issues/196
71
72#![doc(html_root_url = "https://docs.rs/phf/0.12")]
73#![warn(missing_docs)]
74#![cfg_attr(not(feature = "std"), no_std)]
75
76#[cfg(feature = "std")]
77extern crate std as core;
78
79#[cfg(feature = "macros")]
80/// Macro to create a `static` (compile-time) [`Map`].
81///
82/// Requires the `macros` feature.
83///
84/// Supported key expressions are:
85/// - literals: bools, (byte) strings, bytes, chars, and integers (these must have a type suffix)
86/// - arrays of `u8` integers
87/// - dereferenced byte string literals
88/// - `UniCase::unicode(string)`, `UniCase::ascii(string)`, or `Ascii::new(string)` if the `unicase` feature is enabled
89/// - `UncasedStr::new(string)` if the `uncased` feature is enabled
90///
91/// # Example
92///
93/// ```
94/// use phf::{phf_map, Map};
95///
96/// static MY_MAP: Map<&'static str, u32> = phf_map! {
97///     "hello" => 1,
98///     "world" => 2,
99/// };
100///
101/// fn main () {
102///     assert_eq!(MY_MAP["hello"], 1);
103/// }
104/// ```
105pub use phf_macros::phf_map;
106
107#[cfg(feature = "macros")]
108/// Macro to create a `static` (compile-time) [`OrderedMap`].
109///
110/// Requires the `macros` feature. Same usage as [`phf_map`].
111pub use phf_macros::phf_ordered_map;
112
113#[cfg(feature = "macros")]
114/// Macro to create a `static` (compile-time) [`Set`].
115///
116/// Requires the `macros` feature.
117///
118/// # Example
119///
120/// ```
121/// use phf::{phf_set, Set};
122///
123/// static MY_SET: Set<&'static str> = phf_set! {
124///     "hello world",
125///     "hola mundo",
126/// };
127///
128/// fn main () {
129///     assert!(MY_SET.contains("hello world"));
130/// }
131/// ```
132pub use phf_macros::phf_set;
133
134#[cfg(feature = "macros")]
135/// Macro to create a `static` (compile-time) [`OrderedSet`].
136///
137/// Requires the `macros` feature. Same usage as [`phf_set`].
138pub use phf_macros::phf_ordered_set;
139
140#[doc(inline)]
141pub use self::map::Map;
142#[doc(inline)]
143pub use self::ordered_map::OrderedMap;
144#[doc(inline)]
145pub use self::ordered_set::OrderedSet;
146#[doc(inline)]
147pub use self::set::Set;
148pub use phf_shared::PhfHash;
149
150pub mod map;
151pub mod ordered_map;
152pub mod ordered_set;
153pub mod set;
phf/lib.rs

phf/
lib.rs
