Trait AstVisitor 

pub trait AstVisitor: Sized {
    // Provided methods
    fn visit(&mut self, node: &AstNode) { ... }
    fn visit_statement_list(&mut self, stmts: &[AstNode]) { ... }
    fn visit_compilation_unit(&mut self, unit: &CompilationUnit) { ... }
    fn visit_implementation(&mut self, implementation: &Implementation) { ... }
    fn visit_variable_block(&mut self, block: &VariableBlock) { ... }
    fn visit_variable(&mut self, variable: &Variable) { ... }
    fn visit_config_variable(&mut self, config_variable: &ConfigVariable) { ... }
    fn visit_interface(&mut self, interface: &Interface) { ... }
    fn visit_property(&mut self, property: &PropertyBlock) { ... }
    fn visit_enum_element(&mut self, element: &AstNode) { ... }
    fn visit_data_type_declaration(
        &mut self,
        data_type_declaration: &DataTypeDeclaration,
    ) { ... }
    fn visit_user_type_declaration(&mut self, user_type: &UserTypeDeclaration) { ... }
    fn visit_data_type(&mut self, data_type: &DataType) { ... }
    fn visit_pou(&mut self, pou: &Pou) { ... }
    fn visit_empty_statement(&mut self, _stmt: &EmptyStatement, _node: &AstNode) { ... }
    fn visit_default_value(&mut self, _stmt: &DefaultValue, _node: &AstNode) { ... }
    fn visit_literal(&mut self, stmt: &AstLiteral, _node: &AstNode) { ... }
    fn visit_multiplied_statement(
        &mut self,
        stmt: &MultipliedStatement,
        _node: &AstNode,
    ) { ... }
    fn visit_reference_expr(&mut self, stmt: &ReferenceExpr, _node: &AstNode) { ... }
    fn visit_identifier(&mut self, _stmt: &str, _node: &AstNode) { ... }
    fn visit_direct_access(&mut self, stmt: &DirectAccess, _node: &AstNode) { ... }
    fn visit_hardware_access(&mut self, stmt: &HardwareAccess, _node: &AstNode) { ... }
    fn visit_binary_expression(
        &mut self,
        stmt: &BinaryExpression,
        _node: &AstNode,
    ) { ... }
    fn visit_unary_expression(
        &mut self,
        stmt: &UnaryExpression,
        _node: &AstNode,
    ) { ... }
    fn visit_expression_list(&mut self, stmt: &Vec<AstNode>, _node: &AstNode) { ... }
    fn visit_paren_expression(&mut self, inner: &AstNode, _node: &AstNode) { ... }
    fn visit_range_statement(&mut self, stmt: &RangeStatement, _node: &AstNode) { ... }
    fn visit_vla_range_statement(&mut self, _node: &AstNode) { ... }
    fn visit_assignment(&mut self, stmt: &Assignment, _node: &AstNode) { ... }
    fn visit_output_assignment(&mut self, stmt: &Assignment, _node: &AstNode) { ... }
    fn visit_ref_assignment(&mut self, stmt: &Assignment, _node: &AstNode) { ... }
    fn visit_call_statement(&mut self, stmt: &CallStatement, _node: &AstNode) { ... }
    fn visit_control_statement(
        &mut self,
        stmt: &AstControlStatement,
        node: &AstNode,
    ) { ... }
    fn visit_for_loop_statement(
        &mut self,
        stmt: &ForLoopStatement,
        _node: &AstNode,
    ) { ... }
    fn visit_while_loop_statement(
        &mut self,
        stmt: &LoopStatement,
        _node: &AstNode,
    ) { ... }
    fn visit_repeat_loop_statement(
        &mut self,
        stmt: &LoopStatement,
        _node: &AstNode,
    ) { ... }
    fn visit_case_condition(&mut self, child: &AstNode, _node: &AstNode) { ... }
    fn visit_exit_statement(&mut self, _node: &AstNode) { ... }
    fn visit_continue_statement(&mut self, _node: &AstNode) { ... }
    fn visit_return_statement(
        &mut self,
        stmt: &ReturnStatement,
        _node: &AstNode,
    ) { ... }
    fn visit_jump_statement(&mut self, stmt: &JumpStatement, _node: &AstNode) { ... }
    fn visit_label_statement(&mut self, _stmt: &LabelStatement, _node: &AstNode) { ... }
    fn visit_allocation(&mut self, _stmt: &Allocation, _node: &AstNode) { ... }
    fn visit_super(&mut self, _stmt: &AstStatement, _node: &AstNode) { ... }
    fn visit_this(&mut self, _stmt: &AstStatement, _node: &AstNode) { ... }
}

The AstVisitor trait provides a set of methods for visiting different types of AST nodes. Implementors can individually override the methods they are interested in. When overriding a method, make sure to call walk on the visited statement to visit its children. DO NOT call walk on the node itself to avoid a recursion (last parameter). Implementors may also decide to not call the statement’s walk method to avoid visiting the children of the statement.

The visitor offers strongly typed visit_X functions for every node type. The function’s signature is fn visit_X(&mut self, stmt: &X, node: &AstNode). The stmt parameter is the unwrapped, typed node and the node parameter is the AstNode wrapping the stmt. The AstNode node offers access to location information and the AstId. Note that some nodes are not wrapped in an AstNode node (e.g. CompilationUnit) and therefore only the strongly typed node is passed to the visit_X function.

Example

use plc_ast::{
   ast::{Assignment, AstNode},
   visitor::{AstVisitor, Walker},
};

struct AssignmentCounter {
   count: usize,
}

impl AstVisitor for AssignmentCounter {
   fn visit_assignment(&mut self, stmt: &Assignment, _node: &AstNode) {
       self.count += 1;
       // visit child nodes
       stmt.walk(self);
   }

   fn visit_output_assignment(&mut self, stmt: &Assignment, _node: &AstNode) {
       self.count += 1;
       // visit child nodes
       stmt.walk(self);
   }
}

Provided Methods

fn visit(&mut self, node: &AstNode)

Visits this AstNode. The default implementation calls the walk method on the node and will eventually call the strongly typed visit method for the node (e.g. visit_assignment if the node is an AstStatement::Assignment).

Arguments

• node - The AstNode node to visit.

fn visit_statement_list(&mut self, stmts: &[AstNode])

Called when visiting a list of statements (e.g. implementation bodies, control flow branches). Override this to intercept statement-list processing.

fn visit_compilation_unit(&mut self, unit: &CompilationUnit)

Visits a CompilationUnit node. Make sure to call walk on the CompilationUnit node to visit its children.

Arguments

• unit - The unwraped, typed CompilationUnit node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_implementation(&mut self, implementation: &Implementation)

Visits an Implementation node. Make sure to call walk on the Implementation node to visit its children.

Arguments

• implementation - The unwraped, typed Implementation node to visit.

fn visit_variable_block(&mut self, block: &VariableBlock)

Visits a DataTypeDeclaration node. Make sure to call walk on the VariableBlock node to visit its children.

Arguments

• block - The unwraped, typed VariableBlock node to visit.

fn visit_variable(&mut self, variable: &Variable)

Visits a Variable node. Make sure to call walk on the Variable node to visit its children.

Arguments

• variable - The unwraped, typed Variable node to visit.

fn visit_config_variable(&mut self, config_variable: &ConfigVariable)

Visits a ConfigVariable node. Make sure to call walk on the ConfigVariable node to visit its children.

Arguments

• variable - The unwraped, typed Variable node to visit.

fn visit_interface(&mut self, interface: &Interface)

Visits a Interface. Make sure to call walk on the Interface to visit its children.

Arguments

• interface - The unwraped, typed Interface node to visit.

fn visit_property(&mut self, property: &PropertyBlock)

Visits a Property. Make sure to call walk on the PropertyBlock to visit its children.

fn visit_enum_element(&mut self, element: &AstNode)

Visits an enum element AstNode node. Make sure to call walk on the AstNode node to visit its children.

Arguments

• element - The unwraped, typed AstNode node to visit.

fn visit_data_type_declaration( &mut self, data_type_declaration: &DataTypeDeclaration, )

Visits a DataTypeDeclaration node. Make sure to call walk on the DataTypeDeclaration node to visit its children.

Arguments

• data_type_declaration - The unwraped, typed DataTypeDeclaration node to visit.

fn visit_user_type_declaration(&mut self, user_type: &UserTypeDeclaration)

Visits a UserTypeDeclaration node. Make sure to call walk on the UserTypeDeclaration node to visit its children.

Arguments

• user_type - The unwraped, typed UserTypeDeclaration node to visit.

fn visit_data_type(&mut self, data_type: &DataType)

Visits a UserTypeDeclaration node. Make sure to call walk on the DataType node to visit its children.

Arguments

• data_type - The unwraped, typed DataType node to visit.

fn visit_pou(&mut self, pou: &Pou)

Visits a Pou node. Make sure to call walk on the Pou node to visit its children.

Arguments

• pou - The unwraped, typed Pou node to visit.

fn visit_empty_statement(&mut self, _stmt: &EmptyStatement, _node: &AstNode)

Visits an EmptyStatement node.

Arguments

• stmt - The unwraped, typed EmptyStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_default_value(&mut self, _stmt: &DefaultValue, _node: &AstNode)

Visits a DefaultValue node.

Arguments

• stmt - The unwraped, typed DefaultValue node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_literal(&mut self, stmt: &AstLiteral, _node: &AstNode)

Visits an AstLiteral node. Make sure to call walk on the AstLiteral node to visit its children.

Arguments

• stmt - The unwraped, typed AstLiteral node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_multiplied_statement( &mut self, stmt: &MultipliedStatement, _node: &AstNode, )

Visits a MultipliedStatement node. Make sure to call walk on the MultipliedStatement node to visit its children.

Arguments

• stmt - The unwraped, typed MultipliedStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_reference_expr(&mut self, stmt: &ReferenceExpr, _node: &AstNode)

Visits a ReferenceExpr node. Make sure to call walk on the ReferenceExpr node to visit its children.

Arguments

• stmt - The unwraped, typed ReferenceExpr node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_identifier(&mut self, _stmt: &str, _node: &AstNode)

Visits an Identifier node. Make sure to call walk on the Identifier node to visit its children.

Arguments

• stmt - The unwraped, typed Identifier node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_direct_access(&mut self, stmt: &DirectAccess, _node: &AstNode)

Visits a DirectAccess node. Make sure to call walk on the DirectAccess node to visit its children.

Arguments

• stmt - The unwraped, typed DirectAccess node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_hardware_access(&mut self, stmt: &HardwareAccess, _node: &AstNode)

Visits a HardwareAccess node. Make sure to call walk on the HardwareAccess node to visit its children.

Arguments

• stmt - The unwraped, typed HardwareAccess node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_binary_expression(&mut self, stmt: &BinaryExpression, _node: &AstNode)

Visits a BinaryExpression node. Make sure to call walk on the BinaryExpression node to visit its children.

Arguments

• stmt - The unwraped, typed BinaryExpression node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_unary_expression(&mut self, stmt: &UnaryExpression, _node: &AstNode)

Visits a UnaryExpression node. Make sure to call walk on the UnaryExpression node to visit its children.

Arguments

• stmt - The unwraped, typed UnaryExpression node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_expression_list(&mut self, stmt: &Vec<AstNode>, _node: &AstNode)

Visits an ExpressionList node. Make sure to call walk on the Vec<AstNode> node to visit its children.

Arguments

• stmt - The unwraped, typed ExpressionList node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_paren_expression(&mut self, inner: &AstNode, _node: &AstNode)

Visits a ParenExpression node. Make sure to call walk on the inner AstNode node to visit its children.

Arguments

• inner - The unwraped, typed inner AstNode node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_range_statement(&mut self, stmt: &RangeStatement, _node: &AstNode)

Visits a RangeStatement node. Make sure to call walk on the RangeStatement node to visit its children.

Arguments

• stmt - The unwraped, typed RangeStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_vla_range_statement(&mut self, _node: &AstNode)

Visits a VlaRangeStatement node.

Arguments

• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_assignment(&mut self, stmt: &Assignment, _node: &AstNode)

Visits an Assignment node. Make sure to call walk on the Assignment node to visit its children.

Arguments

• stmt - The unwraped, typed Assignment node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_output_assignment(&mut self, stmt: &Assignment, _node: &AstNode)

Visits an OutputAssignment node. Make sure to call walk on the Assignment node to visit its children.

Arguments

• stmt - The unwraped, typed Assignment node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_ref_assignment(&mut self, stmt: &Assignment, _node: &AstNode)

Visits an RefAssignment node. Make sure to call walk on the Assignment node to visit its children.

Arguments

• stmt - The unwraped, typed Assignment node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_call_statement(&mut self, stmt: &CallStatement, _node: &AstNode)

Visits a CallStatement node. Make sure to call walk on the CallStatement node to visit its children.

Arguments

• stmt - The unwraped, typed CallStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_control_statement( &mut self, stmt: &AstControlStatement, node: &AstNode, )

Visits an AstControlStatement node. Make sure to call walk on the AstControlStatement node to visit its children.

Arguments

• stmt - The unwraped, typed AstControlStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_for_loop_statement(&mut self, stmt: &ForLoopStatement, _node: &AstNode)

Visits a ForLoop control statement.

Arguments

• stmt - The unwraped, typed ForLoopStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_while_loop_statement(&mut self, stmt: &LoopStatement, _node: &AstNode)

Visits a WhileLoop control statement. Make sure to call walk on the LoopStatement node to visit its children.

Arguments

• stmt - The unwraped, typed LoopStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_repeat_loop_statement(&mut self, stmt: &LoopStatement, _node: &AstNode)

Visits a RepeatLoop control statement. Make sure to call walk on the LoopStatement node to visit its children.

Arguments

• stmt - The unwraped, typed LoopStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_case_condition(&mut self, child: &AstNode, _node: &AstNode)

Visits a CaseCondition node. Make sure to call walk on the child-AstNode node to visit its children.

Arguments

• stmt - The unwraped, typed CaseCondition node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_exit_statement(&mut self, _node: &AstNode)

Visits an ExitStatement node.

Arguments

• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_continue_statement(&mut self, _node: &AstNode)

Visits a ContinueStatement node.

Arguments

• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_return_statement(&mut self, stmt: &ReturnStatement, _node: &AstNode)

Visits a ReturnStatement node. Make sure to call walk on the ReturnStatement node to visit its children.

Arguments

• stmt - The unwraped, typed ReturnStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_jump_statement(&mut self, stmt: &JumpStatement, _node: &AstNode)

Visits a JumpStatement node. Make sure to call walk on the JumpStatement node to visit its children.

Arguments

• stmt - The unwraped, typed JumpStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_label_statement(&mut self, _stmt: &LabelStatement, _node: &AstNode)

Visits a LabelStatement node.

Arguments

• stmt - The unwraped, typed LabelStatement node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_allocation(&mut self, _stmt: &Allocation, _node: &AstNode)

Visits an Allocation node

Arguments

• stmt - The unwraped, typed Allocation node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_super(&mut self, _stmt: &AstStatement, _node: &AstNode)

Visits a Super node.

Arguments

• stmt - The unwraped, typed Super node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

fn visit_this(&mut self, _stmt: &AstStatement, _node: &AstNode)

Visits a This node.

Arguments

• stmt - The unwraped, typed This node to visit.
• node - The wrapped AstNode node to visit. Offers access to location information and AstId

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

impl AstVisitor for AstSerializer<'_>