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Last update: 15/12/2024

phf_codegen

Compile time static maps for Rust

Latest version: 0.11.2 registry icon
Maintenance score
57
Safety score
100
Popularity score
63
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Security
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0.11.2 0 0 0 0 0
0.11.1 0 0 0 0 0
0.11.0 0 0 0 0 0
0.10.0 0 0 0 0 0
0.9.1 0 0 0 0 0
0.9.0 0 0 0 0 0
0.8.0 0 0 0 0 0
0.7.24 0 0 0 0 0
0.7.23 0 0 0 0 0
0.7.22 0 0 0 0 0
0.7.21 0 0 0 0 0
0.7.20 0 0 0 0 0
0.7.19 0 0 0 0 0
0.7.18 0 0 0 0 0
0.7.17 0 0 0 0 0
0.7.16 0 0 0 0 0
0.7.15 0 0 0 0 0
0.7.14 0 0 0 0 0
0.7.13 0 0 0 0 0
0.7.12 0 0 0 0 0
0.7.11 0 0 0 0 0
0.7.10 0 0 0 0 0
0.7.9 0 0 0 0 0
0.7.8 0 0 0 0 0
0.7.7 0 0 0 0 0
0.7.6 0 0 0 0 0
0.7.5 0 0 0 0 0
0.7.4 0 0 0 0 0
0.7.3 0 0 0 0 0
0.7.2 0 0 0 0 0
0.7.1 0 0 0 0 0
0.7.0 0 0 0 0 0
0.6.19 0 0 0 0 0
0.6.18 0 0 0 0 0
0.6.17 0 0 0 0 0
0.6.15 0 0 0 0 0
0.6.14 0 0 0 0 0
0.6.13 0 0 0 0 0
0.6.12 0 0 0 0 0
0.6.11 0 0 0 0 0
0.6.10 0 0 0 0 0

Stability
Latest release:

0.11.2 - This version is safe to use because it has no known security vulnerabilities at this time. Find out if your coding project uses this component and get notified of any reported security vulnerabilities with Meterian-X Open Source Security Platform

Licensing

Maintain your licence declarations and avoid unwanted licences to protect your IP the way you intended.

MIT   -   MIT License

Not a wildcard

Not proprietary

OSI Compliant

Rust-PHF

CI Latest Version

Documentation

Rust-PHF is a library to generate efficient lookup tables at compile time using perfect hash functions.

It currently uses the CHD algorithm and can generate a 100,000 entry map in roughly .4 seconds.

MSRV (minimum supported rust version) is Rust 1.61.

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.

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:

[dependencies]
# to use `phf` in `no_std` environments
phf = { version = "0.11", default-features = false }

phf_macros

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()
}
[dependencies]
phf = { version = "0.11", features = ["macros"] }

Note

Currently, the macro syntax has some limitations and may not work as you want. See #183 or #196 for example.

phf_codegen

To use phf_codegen on build.rs, you have to add dependencies under [build-dependencies]:

[build-dependencies]
phf = { version = "0.11.1", default-features = false }
phf_codegen = "0.11.1"

Then put code on build.rs:

use std::env;
use std::fs::File;
use std::io::{BufWriter, Write};
use std::path::Path;

fn main() {
    let path = Path::new(&env::var("OUT_DIR").unwrap()).join("codegen.rs");
    let mut file = BufWriter::new(File::create(&path).unwrap());

    write!(
        &mut file,
        "static KEYWORDS: phf::Map<&'static str, Keyword> = {}",
        phf_codegen::Map::new()
            .entry("loop", "Keyword::Loop")
            .entry("continue", "Keyword::Continue")
            .entry("break", "Keyword::Break")
            .entry("fn", "Keyword::Fn")
            .entry("extern", "Keyword::Extern")
            .build()
    )
    .unwrap();
    write!(&mut file, ";\n").unwrap();
}

and lib.rs:

#[derive(Clone)]
enum Keyword {
    Loop,
    Continue,
    Break,
    Fn,
    Extern,
}

include!(concat!(env!("OUT_DIR"), "/codegen.rs"));

pub fn parse_keyword(keyword: &str) -> Option<Keyword> {
    KEYWORDS.get(keyword).cloned()
}