Trait Syntax 

pub trait Syntax:
    Sized
    + Copy
    + Debug
    + Eq {
    // Required methods
    fn from_raw(raw: RawSyntaxKind) -> Self;
    fn into_raw(self) -> RawSyntaxKind;
    fn static_text(self) -> Option<&'static str>;
}

A type that represents what items in your language can be. Typically, this is an enum with variants such as Identifier, Literal, …

The Syntax trait is the bridge between the internal cstree representation and your language’s types. This is essential for providing a SyntaxNode API that can be used with your types, as in the s_expressions example:

#[derive(Debug, Clone, Copy, PartialEq, Eq, cstree::Syntax)]
#[repr(u32)]
enum SyntaxKind {
    #[static_text("+")]
    Plus, // `+`
    #[static_text("-")]
    Minus, // `-`
    Integer,    // like `15`
    Expression, // combined expression, like `5 + 4 - 3`
    Whitespace, // whitespace is explicit
}

cstree provides a procedural macro called cstree_derive to automatically generate Syntax implementations for syntax kind enums if its derive feature is enabled.

Required Methods

fn from_raw(raw: RawSyntaxKind) -> Self

Construct a semantic item kind from the compact representation.

fn into_raw(self) -> RawSyntaxKind

Convert a semantic item kind into a more compact representation.

fn static_text(self) -> Option<&'static str>

Fixed text for a particular syntax kind. Implement for kinds that will only ever represent the same text, such as punctuation (like a semicolon), keywords (like fn), or operators (like <=).

Indicating tokens that have a static_text this way allows cstree to store them more efficiently, which makes it faster to add them to a syntax tree and to look up their text. Since there can often be many occurrences of these tokens inside a file, doing so will improve the performance of using cstree.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors