Trait Keyword

Source

pub(crate) trait Keyword:
    KeywordEncodable
    + Hash
    + Eq
    + PartialEq
    + Copy
    + Clone {
    // Required methods
    fn from_str(s: &str) -> Self;
    fn from_idx(i: usize) -> Option<Self>;
    fn idx(self) -> usize;
    fn n_vals() -> usize;
    fn unrecognized() -> Self;
    fn ann_unrecognized() -> Self;
    fn is_annotation(self) -> bool;

    // Provided methods
    fn idx_to_str(i: usize) -> &'static str { ... }
    fn rule(self) -> TokenFmtBuilder<Self> { ... }
}

Expand description

A Keyword identifies the possible types of a keyword for an Item.

These do not map one-to-one to Item strings: several Item strings may be placed in a single Keyword – for example, when their order is significant with respect to one another, like “accept” and “reject” in router descriptors.

Every keyword has an “index”, which is a small number suitable for indexing an array. These are used in Section and SectionRules.

Turning a string into a keyword cannot fail: there is always an “UNRECOGNIZED” keyword.

See macro::decl_keyword! for help defining a Keyword type for a network document.