Trait Pratt 

pub trait Pratt<L: Language> {
    // Required methods
    fn primary<'a, S: Source + ?Sized>(
        &self,
        state: &mut ParserState<'a, L, S>,
    ) -> &'a GreenNode<'a, L>;
    fn infix<'a, S: Source + ?Sized>(
        &self,
        state: &mut ParserState<'a, L, S>,
        left: &'a GreenNode<'a, L>,
        min_precedence: u8,
    ) -> Option<&'a GreenNode<'a, L>>;

    // Provided method
    fn prefix<'a, S: Source + ?Sized>(
        &self,
        state: &mut ParserState<'a, L, S>,
    ) -> &'a GreenNode<'a, L> { ... }
}

A specification for a Pratt parser.

Users implement this trait to define the grammar rules for expressions. Using a trait allows the compiler to optimize operator lookups using match statements.

Required Methods

fn primary<'a, S: Source + ?Sized>( &self, state: &mut ParserState<'a, L, S>, ) -> &'a GreenNode<'a, L>

Parses a primary expression (e.g., literals, identifiers, group).

fn infix<'a, S: Source + ?Sized>( &self, state: &mut ParserState<'a, L, S>, left: &'a GreenNode<'a, L>, min_precedence: u8, ) -> Option<&'a GreenNode<'a, L>>

Handles infix and postfix operators.

Should return Some(new_node) if an operator was parsed, or None if no operator matches or its precedence is lower than min_precedence.

Provided Methods

fn prefix<'a, S: Source + ?Sized>( &self, state: &mut ParserState<'a, L, S>, ) -> &'a GreenNode<'a, L>

Handles prefix operators and primary expressions.

Default implementation just calls primary.

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