Trait Visit

source

pub trait Visit<'ast, 'text> {
Show 31 methods    // Provided methods
    fn visit_message(&mut self, message: &'ast Message<'text>) { ... }
    fn visit_pattern(&mut self, msg: &'ast Pattern<'text>) { ... }
    fn visit_pattern_part(&mut self, part: &'ast PatternPart<'text>) { ... }
    fn visit_text(&mut self, text: &'ast Text<'text>) { ... }
    fn visit_escape(&mut self, escape: &'ast Escape) { ... }
    fn visit_expression(&mut self, expr: &'ast Expression<'text>) { ... }
    fn visit_literal_expression(&mut self, expr: &'ast LiteralExpression<'text>) { ... }
    fn visit_literal(&mut self, literal: &'ast Literal<'text>) { ... }
    fn visit_quoted(&mut self, quoted: &'ast Quoted<'text>) { ... }
    fn visit_quoted_part(&mut self, part: &'ast QuotedPart<'text>) { ... }
    fn visit_number(&mut self, num: &'ast Number<'text>) { ... }
    fn visit_annotation(&mut self, ann: &'ast Annotation<'text>) { ... }
    fn visit_function(&mut self, func: &'ast Function<'text>) { ... }
    fn visit_identifier(&mut self, ident: &'ast Identifier<'text>) { ... }
    fn visit_fn_or_markup_option(&mut self, opt: &'ast FnOrMarkupOption<'text>) { ... }
    fn visit_literal_or_variable(
        &mut self,
        lit_or_var: &'ast LiteralOrVariable<'text>,
    ) { ... }
    fn visit_variable(&mut self, var: &'ast Variable<'text>) { ... }
    fn visit_attribute(&mut self, attr: &'ast Attribute<'text>) { ... }
    fn visit_variable_expression(
        &mut self,
        expr: &'ast VariableExpression<'text>,
    ) { ... }
    fn visit_annotation_expression(
        &mut self,
        expr: &'ast AnnotationExpression<'text>,
    ) { ... }
    fn visit_markup(&mut self, markup: &'ast Markup<'text>) { ... }
    fn visit_complex_message(&mut self, msg: &'ast ComplexMessage<'text>) { ... }
    fn visit_declaration(&mut self, decl: &'ast Declaration<'text>) { ... }
    fn visit_input_declaration(&mut self, decl: &'ast InputDeclaration<'text>) { ... }
    fn visit_local_declaration(&mut self, decl: &'ast LocalDeclaration<'text>) { ... }
    fn visit_complex_message_body(
        &mut self,
        body: &'ast ComplexMessageBody<'text>,
    ) { ... }
    fn visit_quoted_pattern(&mut self, pattern: &'ast QuotedPattern<'text>) { ... }
    fn visit_matcher(&mut self, matcher: &'ast Matcher<'text>) { ... }
    fn visit_variant(&mut self, variant: &'ast Variant<'text>) { ... }
    fn visit_key(&mut self, key: &'ast Key<'text>) { ... }
    fn visit_star(&mut self, star: &'ast Star) { ... }
}

Expand description

The Visit trait is used to traverse the AST. You can implement this trait to visit each node in the AST in source text order.

Each method in the trait corresponds to a node type in the AST. The method is called with a reference to the node. The default implementation of each method calls Visitable::apply_visitor_to_children on the node, which then recursively applies the visitor to the node’s children. To implement a recursive visitor, you must also call Visitable::apply_visitor_to_children on any overridden visit methods.

§Example

use mf2_parser::ast::*;
use mf2_parser::Visit;
use mf2_parser::Visitable as _;
use mf2_parser::parse;

struct MyVisitor;

impl<'ast, 'text> Visit<'ast, 'text> for MyVisitor {
  fn visit_variable(&mut self, var: &'ast Variable<'text>) {
    println!("Found variable: {}", var.name);
    var.apply_visitor_to_children(self);
  }
}


let (ast, _, _) = parse("Hello, {$name}!");
let mut visitor = MyVisitor;
ast.apply_visitor(&mut visitor);