phf

This crate creates a perfect hash function for an enum, providing a single method: T::lookup(&str) -> Option<T>

This method will return either the exact match of the variant, or None

std::fmt::Display is also implemented for convenient printing of the string representation of the variant

Examples:

derive

Derive a perfect hash on a enum, uses the variant names, as lowercase in the PHF:

use phf::PerfectHash;
#[derive(PerfectHash, Debug, PartialEq)]
enum Keyword {
    Fn,
    When,
    If,
    Then,
    Else,
    Where,
    Select,
    Return
}

assert_eq!(Keyword::lookup("when"), Some(Keyword::When));
assert_eq!(Keyword::lookup("asdf"), None);

mapping

Use a macro to create an enum for things that can't be trivially converted via their name:

use phf::{PerfectHash, phf_mapping};
// This takes in an enum name to generate, then the variants and what they should map to:
phf_mapping! { Sigil =>
    Pipe = "<|",
    FDiv = "/.",
    IDIv = "//",
};

assert_eq!(Sigil::lookup("<|"), Some(Sigil::Pipe));