Interpreter - Refactored internals out of the node implemntations
This commit is contained in:
parent
b01ae10d09
commit
18d9bfb74c
1 changed files with 371 additions and 402 deletions
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@ -1,7 +1,10 @@
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use std::{cell::RefCell, collections::HashMap, rc::Rc};
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use crate::{
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ast::{ClassDecl, ExprNode, FunDecl, GetExpr, ProgramNode, SetExpr, StmtNode, VariableExpr},
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ast::{
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ClassDecl, ExprNode, FunDecl, GetExpr, ProgramNode, SetExpr, StmtNode, SuperExpr,
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VariableExpr,
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},
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errors::{ErrorKind, SloxError, SloxResult},
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resolver::ResolvedVariables,
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tokens::{Token, TokenType},
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@ -128,9 +131,9 @@ fn error<T>(token: &Token, message: &str) -> SloxResult<T> {
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))
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}
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/* ----------------------------- *
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* INTERPRETER FOR PROGRAM NODES *
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* ----------------------------- */
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/* -------------------------- *
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* ENTRY POINTS FOR AST NODES *
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* -------------------------- */
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impl Interpretable for ProgramNode {
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fn interpret(&self, es: &mut InterpreterState) -> InterpreterResult {
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@ -141,39 +144,85 @@ impl Interpretable for ProgramNode {
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}
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}
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/* ------------------------------- *
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* INTERPRETER FOR STATEMENT NODES *
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* ------------------------------- */
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impl Interpretable for StmtNode {
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fn interpret(&self, es: &mut InterpreterState) -> InterpreterResult {
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match self {
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StmtNode::VarDecl(name, expr) => self.on_var_decl(es, name, expr),
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StmtNode::FunDecl(decl) => self.on_fun_decl(es, decl),
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StmtNode::ClassDecl(decl) => self.on_class_decl(es, decl),
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StmtNode::VarDecl(name, expr) => on_var_decl(es, name, expr),
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StmtNode::FunDecl(decl) => on_fun_decl(es, decl),
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StmtNode::ClassDecl(decl) => on_class_decl(es, decl),
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StmtNode::Expression(expr) => expr.interpret(es),
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StmtNode::Print(expr) => self.on_print(es, expr),
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StmtNode::Block(statements) => self.on_block(es, statements),
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StmtNode::Print(expr) => on_print(es, expr),
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StmtNode::Block(statements) => on_block(es, statements),
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StmtNode::If {
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condition,
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then_branch,
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else_branch,
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} => self.on_if_statement(es, condition, then_branch, else_branch),
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} => on_if_statement(es, condition, then_branch, else_branch),
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StmtNode::Loop {
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label,
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condition,
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body,
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after_body,
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} => self.on_loop_statement(es, label, condition, body, after_body),
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} => on_loop_statement(es, label, condition, body, after_body),
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StmtNode::LoopControl {
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is_break,
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loop_name,
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} => self.on_loop_control_statemement(*is_break, loop_name),
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StmtNode::Return { token: _, value } => self.on_return_statement(es, value),
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} => on_loop_control_statemement(*is_break, loop_name),
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StmtNode::Return { token: _, value } => on_return_statement(es, value),
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}
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}
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}
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impl Interpretable for ExprNode {
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fn interpret(&self, es: &mut InterpreterState) -> InterpreterResult {
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match self {
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ExprNode::Assignment { name, value, id } => {
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let value = value.interpret(es)?.result();
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es.assign_var(name, id, value)?;
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Ok(InterpreterFlowControl::default())
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}
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ExprNode::Logical(binary_expr) => on_logic(
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es,
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&binary_expr.left,
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&binary_expr.operator,
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&binary_expr.right,
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),
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ExprNode::Binary(binary_expr) => on_binary(
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es,
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&binary_expr.left,
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&binary_expr.operator,
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&binary_expr.right,
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),
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ExprNode::Unary { operator, right } => on_unary(es, operator, right),
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ExprNode::Grouping { expression } => expression.interpret(es),
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ExprNode::Litteral { value } => on_litteral(value),
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ExprNode::Variable(var_expr) | ExprNode::This(var_expr) => var_expr.interpret(es),
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ExprNode::Call {
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callee,
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right_paren,
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arguments,
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} => on_call(es, callee, right_paren, arguments),
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ExprNode::Lambda { params, body } => {
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let lambda = Function::new(None, params, body, es.environment.clone(), false);
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Ok(Value::from(lambda).into())
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}
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ExprNode::Get(get_expr) => on_get_expression(es, get_expr),
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ExprNode::Set(set_expr) => on_set_expression(es, set_expr),
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ExprNode::Super(super_expr) => on_super(es, super_expr),
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}
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}
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}
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impl Interpretable for VariableExpr {
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fn interpret(&self, es: &mut InterpreterState) -> InterpreterResult {
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Ok(es.lookup_var(self)?.into())
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}
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}
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/* --------------------- *
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* INTERPRETER INTERNALS *
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* --------------------- */
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/// Extract members from a class declaration, generating a map of
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/// functions.
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fn extract_members(
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@ -198,425 +247,345 @@ fn extract_members(
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.collect()
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}
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impl StmtNode {
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/// Handle the `print` statement.
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fn on_print(&self, es: &mut InterpreterState, expr: &ExprNode) -> InterpreterResult {
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let value = expr.interpret(es)?.result();
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let output = value.to_string();
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println!("{}", output);
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Ok(InterpreterFlowControl::default())
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}
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/// Handle the `print` statement.
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fn on_print(es: &mut InterpreterState, expr: &ExprNode) -> InterpreterResult {
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let value = expr.interpret(es)?.result();
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let output = value.to_string();
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println!("{}", output);
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Ok(InterpreterFlowControl::default())
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}
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/// Handle a variable declaration.
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fn on_var_decl(
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&self,
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es: &mut InterpreterState,
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name: &Token,
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initializer: &Option<ExprNode>,
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) -> InterpreterResult {
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let variable = match initializer {
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Some(expr) => Some(expr.interpret(es)?.result()),
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None => None,
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};
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es.environment.borrow_mut().define(name, variable)?;
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Ok(InterpreterFlowControl::default())
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}
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/// Handle a variable declaration.
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fn on_var_decl(
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es: &mut InterpreterState,
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name: &Token,
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initializer: &Option<ExprNode>,
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) -> InterpreterResult {
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let variable = match initializer {
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Some(expr) => Some(expr.interpret(es)?.result()),
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None => None,
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};
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es.environment.borrow_mut().define(name, variable)?;
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Ok(InterpreterFlowControl::default())
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}
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/// Handle a class declaration
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fn on_class_decl(&self, es: &mut InterpreterState, decl: &ClassDecl) -> InterpreterResult {
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es.environment.borrow_mut().define(&decl.name, None)?;
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let class = match &decl.superclass {
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None => Class::new(decl.name.lexeme.clone(), None, extract_members(es, decl)),
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Some(superclass) => {
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let sc_value = superclass.interpret(es)?.result();
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let sc_ref = if let Some(sc_ref) = sc_value.as_class_ref() {
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Some(sc_ref)
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} else {
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return error(&superclass.token, "superclass must be a class");
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};
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let mut sub_env = InterpreterState::create_child(es);
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sub_env
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.environment
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.borrow_mut()
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.set("super", sc_value.clone());
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Class::new(
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decl.name.lexeme.clone(),
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sc_ref,
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extract_members(&mut sub_env, decl),
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)
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}
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};
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es.environment
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.borrow_mut()
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.assign(&decl.name, class.into())?;
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Ok(InterpreterFlowControl::default())
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}
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/// Handle a function declaration.
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fn on_fun_decl(&self, es: &mut InterpreterState, decl: &FunDecl) -> InterpreterResult {
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let fun = Function::new(
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Some(&decl.name),
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&decl.params,
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&decl.body,
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es.environment.clone(),
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false,
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);
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es.environment
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.borrow_mut()
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.define(&decl.name, Some(fun.into()))?;
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Ok(InterpreterFlowControl::default())
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}
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/// Execute the contents of a block.
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fn on_block(&self, es: &mut InterpreterState, stmts: &[StmtNode]) -> InterpreterResult {
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let mut child = InterpreterState::create_child(es);
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for stmt in stmts.iter() {
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let result = stmt.interpret(&mut child)?;
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if result.is_flow_control() {
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return Ok(result);
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}
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/// Handle a class declaration
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fn on_class_decl(es: &mut InterpreterState, decl: &ClassDecl) -> InterpreterResult {
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es.environment.borrow_mut().define(&decl.name, None)?;
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let class = match &decl.superclass {
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None => Class::new(decl.name.lexeme.clone(), None, extract_members(es, decl)),
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Some(superclass) => {
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let sc_value = superclass.interpret(es)?.result();
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let sc_ref = if let Some(sc_ref) = sc_value.as_class_ref() {
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Some(sc_ref)
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} else {
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return error(&superclass.token, "superclass must be a class");
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};
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let mut sub_env = InterpreterState::create_child(es);
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sub_env
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.environment
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.borrow_mut()
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.set("super", sc_value.clone());
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Class::new(
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decl.name.lexeme.clone(),
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sc_ref,
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extract_members(&mut sub_env, decl),
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)
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}
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Ok(InterpreterFlowControl::default())
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}
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};
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es.environment
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.borrow_mut()
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.assign(&decl.name, class.into())?;
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Ok(InterpreterFlowControl::default())
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}
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/// Execute an if statement.
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fn on_if_statement(
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&self,
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es: &mut InterpreterState,
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condition: &ExprNode,
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then_branch: &StmtNode,
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else_branch: &Option<Box<StmtNode>>,
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) -> InterpreterResult {
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if condition.interpret(es)?.result().is_truthy() {
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then_branch.interpret(es)
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} else if let Some(else_stmt) = else_branch {
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else_stmt.interpret(es)
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} else {
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Ok(InterpreterFlowControl::default())
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/// Handle a function declaration.
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fn on_fun_decl(es: &mut InterpreterState, decl: &FunDecl) -> InterpreterResult {
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let fun = Function::new(
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Some(&decl.name),
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&decl.params,
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&decl.body,
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es.environment.clone(),
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false,
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);
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es.environment
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.borrow_mut()
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.define(&decl.name, Some(fun.into()))?;
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Ok(InterpreterFlowControl::default())
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}
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/// Execute the contents of a block.
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fn on_block(es: &mut InterpreterState, stmts: &[StmtNode]) -> InterpreterResult {
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let mut child = InterpreterState::create_child(es);
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for stmt in stmts.iter() {
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let result = stmt.interpret(&mut child)?;
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if result.is_flow_control() {
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return Ok(result);
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}
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}
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Ok(InterpreterFlowControl::default())
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}
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/// Execute a while statement.
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fn on_loop_statement(
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&self,
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es: &mut InterpreterState,
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label: &Option<Token>,
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condition: &ExprNode,
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body: &StmtNode,
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after_body: &Option<Box<StmtNode>>,
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) -> InterpreterResult {
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let ln = label.as_ref().map(|token| token.lexeme.clone());
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while condition.interpret(es)?.result().is_truthy() {
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let result = body.interpret(es)?;
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/// Execute an if statement.
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fn on_if_statement(
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es: &mut InterpreterState,
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condition: &ExprNode,
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then_branch: &StmtNode,
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else_branch: &Option<Box<StmtNode>>,
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) -> InterpreterResult {
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if condition.interpret(es)?.result().is_truthy() {
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then_branch.interpret(es)
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} else if let Some(else_stmt) = else_branch {
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else_stmt.interpret(es)
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} else {
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Ok(InterpreterFlowControl::default())
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}
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}
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/// Execute a while statement.
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fn on_loop_statement(
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es: &mut InterpreterState,
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label: &Option<Token>,
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condition: &ExprNode,
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body: &StmtNode,
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after_body: &Option<Box<StmtNode>>,
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) -> InterpreterResult {
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let ln = label.as_ref().map(|token| token.lexeme.clone());
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while condition.interpret(es)?.result().is_truthy() {
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let result = body.interpret(es)?;
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match &result {
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InterpreterFlowControl::Result(_) => (),
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InterpreterFlowControl::Continue(lv) if lv == &ln => (),
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InterpreterFlowControl::Break(lv) if lv == &ln => break,
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_ => return Ok(result),
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}
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if let Some(stmt) = after_body {
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let result = stmt.interpret(es)?;
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match &result {
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InterpreterFlowControl::Result(_) => (),
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InterpreterFlowControl::Continue(lv) if lv == &ln => (),
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InterpreterFlowControl::Break(lv) if lv == &ln => break,
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_ => return Ok(result),
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}
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if let Some(stmt) = after_body {
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let result = stmt.interpret(es)?;
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match &result {
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InterpreterFlowControl::Result(_) => (),
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InterpreterFlowControl::Continue(lv) if lv == &ln => (),
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InterpreterFlowControl::Break(lv) if lv == &ln => break,
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_ => return Ok(result),
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}
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}
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}
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Ok(InterpreterFlowControl::default())
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}
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/// Execute a loop control statement.
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fn on_loop_control_statemement(
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&self,
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is_break: bool,
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label: &Option<Token>,
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) -> InterpreterResult {
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let name = label.as_ref().map(|token| token.lexeme.clone());
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if is_break {
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Ok(InterpreterFlowControl::Break(name))
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} else {
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Ok(InterpreterFlowControl::Continue(name))
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}
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}
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Ok(InterpreterFlowControl::default())
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}
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/// Execute a return statement.
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fn on_return_statement(
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&self,
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es: &mut InterpreterState,
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value: &Option<ExprNode>,
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) -> InterpreterResult {
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let rv = match value {
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None => Value::Nil,
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Some(expr) => expr.interpret(es)?.result(),
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};
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Ok(InterpreterFlowControl::Return(rv))
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/// Execute a loop control statement.
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fn on_loop_control_statemement(is_break: bool, label: &Option<Token>) -> InterpreterResult {
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let name = label.as_ref().map(|token| token.lexeme.clone());
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if is_break {
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Ok(InterpreterFlowControl::Break(name))
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} else {
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Ok(InterpreterFlowControl::Continue(name))
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}
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}
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/* -------------------------------- *
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* INTERPRETER FOR EXPRESSION NODES *
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* -------------------------------- */
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/// Execute a return statement.
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fn on_return_statement(es: &mut InterpreterState, value: &Option<ExprNode>) -> InterpreterResult {
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let rv = match value {
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None => Value::Nil,
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Some(expr) => expr.interpret(es)?.result(),
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};
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Ok(InterpreterFlowControl::Return(rv))
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}
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impl Interpretable for ExprNode {
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fn interpret(&self, es: &mut InterpreterState) -> InterpreterResult {
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match self {
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ExprNode::Assignment { name, value, id } => {
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let value = value.interpret(es)?.result();
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es.assign_var(name, id, value)?;
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Ok(InterpreterFlowControl::default())
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}
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ExprNode::Logical(binary_expr) => self.on_logic(
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es,
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&binary_expr.left,
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&binary_expr.operator,
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&binary_expr.right,
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),
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ExprNode::Binary(binary_expr) => self.on_binary(
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es,
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&binary_expr.left,
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&binary_expr.operator,
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&binary_expr.right,
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),
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ExprNode::Unary { operator, right } => self.on_unary(es, operator, right),
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ExprNode::Grouping { expression } => expression.interpret(es),
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ExprNode::Litteral { value } => self.on_litteral(value),
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ExprNode::Variable(var_expr) | ExprNode::This(var_expr) => var_expr.interpret(es),
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ExprNode::Call {
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callee,
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right_paren,
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arguments,
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} => self.on_call(es, callee, right_paren, arguments),
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ExprNode::Lambda { params, body } => {
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let lambda = Function::new(None, params, body, es.environment.clone(), false);
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Ok(Value::from(lambda).into())
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}
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ExprNode::Get(get_expr) => self.on_get_expression(es, get_expr),
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ExprNode::Set(set_expr) => self.on_set_expression(es, set_expr),
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ExprNode::Super(super_expr) => {
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let distance = match es.locals.get(&super_expr.keyword.id) {
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Some(distance) => *distance,
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None => panic!("super environment not found"),
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};
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assert!(distance > 0);
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let obj_ref = es.environment.borrow().get_at(
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distance - 1,
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&Token {
|
||||
token_type: TokenType::This,
|
||||
lexeme: "this".to_owned(),
|
||||
line: 0,
|
||||
},
|
||||
)?;
|
||||
Ok(obj_ref
|
||||
.with_property_carrier(
|
||||
|inst| inst.get_super(es, &super_expr, distance),
|
||||
|| panic!("'this' didn't contain an instance"),
|
||||
)?
|
||||
.into())
|
||||
}
|
||||
}
|
||||
/// Evaluate a logical operator.
|
||||
fn on_logic(
|
||||
es: &mut InterpreterState,
|
||||
left: &ExprNode,
|
||||
operator: &Token,
|
||||
right: &ExprNode,
|
||||
) -> InterpreterResult {
|
||||
let left_value = left.interpret(es)?.result();
|
||||
if operator.token_type == TokenType::Or && left_value.is_truthy()
|
||||
|| operator.token_type == TokenType::And && !left_value.is_truthy()
|
||||
{
|
||||
Ok(left_value.into())
|
||||
} else {
|
||||
right.interpret(es)
|
||||
}
|
||||
}
|
||||
|
||||
impl Interpretable for VariableExpr {
|
||||
fn interpret(&self, es: &mut InterpreterState) -> InterpreterResult {
|
||||
Ok(es.lookup_var(self)?.into())
|
||||
}
|
||||
}
|
||||
/// Evaluate a binary operator.
|
||||
fn on_binary(
|
||||
es: &mut InterpreterState,
|
||||
left: &ExprNode,
|
||||
operator: &Token,
|
||||
right: &ExprNode,
|
||||
) -> InterpreterResult {
|
||||
let left_value = left.interpret(es)?.result();
|
||||
let right_value = right.interpret(es)?.result();
|
||||
match operator.token_type {
|
||||
TokenType::Plus => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Number(a + b).into()),
|
||||
(Value::String(a), Value::String(b)) => Ok(Value::String(a + &b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
impl ExprNode {
|
||||
/// Evaluate a logical operator.
|
||||
fn on_logic(
|
||||
&self,
|
||||
es: &mut InterpreterState,
|
||||
left: &ExprNode,
|
||||
operator: &Token,
|
||||
right: &ExprNode,
|
||||
) -> InterpreterResult {
|
||||
let left_value = left.interpret(es)?.result();
|
||||
if operator.token_type == TokenType::Or && left_value.is_truthy()
|
||||
|| operator.token_type == TokenType::And && !left_value.is_truthy()
|
||||
{
|
||||
Ok(left_value.into())
|
||||
} else {
|
||||
right.interpret(es)
|
||||
}
|
||||
}
|
||||
TokenType::Minus => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Number(a - b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
/// Evaluate a binary operator.
|
||||
fn on_binary(
|
||||
&self,
|
||||
es: &mut InterpreterState,
|
||||
left: &ExprNode,
|
||||
operator: &Token,
|
||||
right: &ExprNode,
|
||||
) -> InterpreterResult {
|
||||
let left_value = left.interpret(es)?.result();
|
||||
let right_value = right.interpret(es)?.result();
|
||||
match operator.token_type {
|
||||
TokenType::Plus => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Number(a + b).into()),
|
||||
(Value::String(a), Value::String(b)) => Ok(Value::String(a + &b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
TokenType::Star => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Number(a * b).into()),
|
||||
(Value::String(a), Value::Number(b)) => Ok(Value::String(a.repeat(b as usize)).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::Minus => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Number(a - b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::Star => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Number(a * b).into()),
|
||||
(Value::String(a), Value::Number(b)) => {
|
||||
Ok(Value::String(a.repeat(b as usize)).into())
|
||||
}
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::Slash => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => {
|
||||
if b == 0. {
|
||||
error(operator, "division by zero")
|
||||
} else {
|
||||
Ok(Value::Number(a / b).into())
|
||||
}
|
||||
}
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::Greater => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a > b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::GreaterEqual => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a >= b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::Less => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a < b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::LessEqual => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a <= b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::EqualEqual => Ok(Value::Boolean(left_value == right_value).into()),
|
||||
TokenType::BangEqual => Ok(Value::Boolean(left_value != right_value).into()),
|
||||
|
||||
_ => panic!(
|
||||
"Unsupported token type for binary operator (token {:?})",
|
||||
operator
|
||||
),
|
||||
}
|
||||
}
|
||||
|
||||
/// Evaluate an unary operator.
|
||||
fn on_unary(
|
||||
&self,
|
||||
es: &mut InterpreterState,
|
||||
operator: &Token,
|
||||
right: &ExprNode,
|
||||
) -> InterpreterResult {
|
||||
let right_value = right.interpret(es)?.result();
|
||||
match operator.token_type {
|
||||
TokenType::Minus => {
|
||||
if let Value::Number(n) = right_value {
|
||||
Ok(Value::Number(-n).into())
|
||||
TokenType::Slash => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => {
|
||||
if b == 0. {
|
||||
error(operator, "division by zero")
|
||||
} else {
|
||||
error(operator, "number expected")
|
||||
Ok(Value::Number(a / b).into())
|
||||
}
|
||||
}
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
TokenType::Bang => Ok(Value::Boolean(!right_value.is_truthy()).into()),
|
||||
TokenType::Greater => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a > b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
_ => panic!(
|
||||
"Unsupported token type for unary operator (token {:?})",
|
||||
operator
|
||||
),
|
||||
}
|
||||
}
|
||||
TokenType::GreaterEqual => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a >= b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
/// Evaluate a litteral.
|
||||
fn on_litteral(&self, value: &Token) -> InterpreterResult {
|
||||
let out_value = match &value.token_type {
|
||||
TokenType::Nil => Value::Nil,
|
||||
TokenType::True => Value::Boolean(true),
|
||||
TokenType::False => Value::Boolean(false),
|
||||
TokenType::Number(n) => Value::Number(*n),
|
||||
TokenType::String(s) => Value::String(s.clone()),
|
||||
_ => panic!("Unsupported token type for litteral (token {:?})", value),
|
||||
};
|
||||
Ok(out_value.into())
|
||||
}
|
||||
TokenType::Less => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a < b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
/// Evaluate a function call.
|
||||
fn on_call(
|
||||
&self,
|
||||
es: &mut InterpreterState,
|
||||
callee: &ExprNode,
|
||||
right_paren: &Token,
|
||||
arguments: &Vec<ExprNode>,
|
||||
) -> InterpreterResult {
|
||||
let callee = callee.interpret(es)?.result();
|
||||
let arg_values = {
|
||||
let mut v = Vec::with_capacity(arguments.len());
|
||||
for argument in arguments.iter() {
|
||||
v.push(argument.interpret(es)?.result());
|
||||
}
|
||||
v
|
||||
};
|
||||
callee.with_callable(
|
||||
|callable| {
|
||||
if callable.arity() != arg_values.len() {
|
||||
Err(SloxError::with_token(
|
||||
ErrorKind::Runtime,
|
||||
right_paren,
|
||||
format!(
|
||||
"expected {} arguments, found {}",
|
||||
arg_values.len(),
|
||||
callable.arity()
|
||||
),
|
||||
))
|
||||
} else {
|
||||
Ok(callable.call(es, arg_values)?.into())
|
||||
}
|
||||
},
|
||||
|| error(right_paren, "expression result is not callable"),
|
||||
)
|
||||
}
|
||||
TokenType::LessEqual => match (left_value, right_value) {
|
||||
(Value::Number(a), Value::Number(b)) => Ok(Value::Boolean(a <= b).into()),
|
||||
_ => error(operator, "type error"),
|
||||
},
|
||||
|
||||
/// Evaluate a get expression.
|
||||
fn on_get_expression(
|
||||
&self,
|
||||
itpr_state: &mut InterpreterState,
|
||||
get_expr: &GetExpr,
|
||||
) -> InterpreterResult {
|
||||
let instance = get_expr.instance.interpret(itpr_state)?.result();
|
||||
instance.with_property_carrier(
|
||||
|inst| inst.get(itpr_state, &get_expr.name).map(|v| v.into()),
|
||||
|| error(&get_expr.name, "this object doesn't have properties"),
|
||||
)
|
||||
}
|
||||
TokenType::EqualEqual => Ok(Value::Boolean(left_value == right_value).into()),
|
||||
TokenType::BangEqual => Ok(Value::Boolean(left_value != right_value).into()),
|
||||
|
||||
/// Evaluate a set expression.
|
||||
fn on_set_expression(
|
||||
&self,
|
||||
itpr_state: &mut InterpreterState,
|
||||
set_expr: &SetExpr,
|
||||
) -> InterpreterResult {
|
||||
let instance = set_expr.instance.interpret(itpr_state)?.result();
|
||||
instance.with_property_carrier(
|
||||
|instance| {
|
||||
let value = set_expr.value.interpret(itpr_state)?.result();
|
||||
instance.set(itpr_state, &set_expr.name, value.clone());
|
||||
Ok(value.into())
|
||||
},
|
||||
|| error(&set_expr.name, "this object doesn't have properties"),
|
||||
)
|
||||
_ => panic!(
|
||||
"Unsupported token type for binary operator (token {:?})",
|
||||
operator
|
||||
),
|
||||
}
|
||||
}
|
||||
|
||||
/// Evaluate an unary operator.
|
||||
fn on_unary(es: &mut InterpreterState, operator: &Token, right: &ExprNode) -> InterpreterResult {
|
||||
let right_value = right.interpret(es)?.result();
|
||||
match operator.token_type {
|
||||
TokenType::Minus => {
|
||||
if let Value::Number(n) = right_value {
|
||||
Ok(Value::Number(-n).into())
|
||||
} else {
|
||||
error(operator, "number expected")
|
||||
}
|
||||
}
|
||||
|
||||
TokenType::Bang => Ok(Value::Boolean(!right_value.is_truthy()).into()),
|
||||
|
||||
_ => panic!(
|
||||
"Unsupported token type for unary operator (token {:?})",
|
||||
operator
|
||||
),
|
||||
}
|
||||
}
|
||||
|
||||
/// Evaluate a litteral.
|
||||
fn on_litteral(value: &Token) -> InterpreterResult {
|
||||
let out_value = match &value.token_type {
|
||||
TokenType::Nil => Value::Nil,
|
||||
TokenType::True => Value::Boolean(true),
|
||||
TokenType::False => Value::Boolean(false),
|
||||
TokenType::Number(n) => Value::Number(*n),
|
||||
TokenType::String(s) => Value::String(s.clone()),
|
||||
_ => panic!("Unsupported token type for litteral (token {:?})", value),
|
||||
};
|
||||
Ok(out_value.into())
|
||||
}
|
||||
|
||||
/// Evaluate a function call.
|
||||
fn on_call(
|
||||
es: &mut InterpreterState,
|
||||
callee: &ExprNode,
|
||||
right_paren: &Token,
|
||||
arguments: &Vec<ExprNode>,
|
||||
) -> InterpreterResult {
|
||||
let callee = callee.interpret(es)?.result();
|
||||
let arg_values = {
|
||||
let mut v = Vec::with_capacity(arguments.len());
|
||||
for argument in arguments.iter() {
|
||||
v.push(argument.interpret(es)?.result());
|
||||
}
|
||||
v
|
||||
};
|
||||
callee.with_callable(
|
||||
|callable| {
|
||||
if callable.arity() != arg_values.len() {
|
||||
Err(SloxError::with_token(
|
||||
ErrorKind::Runtime,
|
||||
right_paren,
|
||||
format!(
|
||||
"expected {} arguments, found {}",
|
||||
arg_values.len(),
|
||||
callable.arity()
|
||||
),
|
||||
))
|
||||
} else {
|
||||
Ok(callable.call(es, arg_values)?.into())
|
||||
}
|
||||
},
|
||||
|| error(right_paren, "expression result is not callable"),
|
||||
)
|
||||
}
|
||||
|
||||
/// Evaluate a get expression.
|
||||
fn on_get_expression(itpr_state: &mut InterpreterState, get_expr: &GetExpr) -> InterpreterResult {
|
||||
let instance = get_expr.instance.interpret(itpr_state)?.result();
|
||||
instance.with_property_carrier(
|
||||
|inst| inst.get(itpr_state, &get_expr.name).map(|v| v.into()),
|
||||
|| error(&get_expr.name, "this object doesn't have properties"),
|
||||
)
|
||||
}
|
||||
|
||||
/// Evaluate a set expression.
|
||||
fn on_set_expression(itpr_state: &mut InterpreterState, set_expr: &SetExpr) -> InterpreterResult {
|
||||
let instance = set_expr.instance.interpret(itpr_state)?.result();
|
||||
instance.with_property_carrier(
|
||||
|instance| {
|
||||
let value = set_expr.value.interpret(itpr_state)?.result();
|
||||
instance.set(itpr_state, &set_expr.name, value.clone());
|
||||
Ok(value.into())
|
||||
},
|
||||
|| error(&set_expr.name, "this object doesn't have properties"),
|
||||
)
|
||||
}
|
||||
|
||||
/// Evaluate a reference to a superclass method.
|
||||
fn on_super(itpr_state: &mut InterpreterState, super_expr: &SuperExpr) -> InterpreterResult {
|
||||
let distance = match itpr_state.locals.get(&super_expr.keyword.id) {
|
||||
Some(distance) => *distance,
|
||||
None => panic!("super environment not found"),
|
||||
};
|
||||
assert!(distance > 0);
|
||||
let obj_ref = itpr_state.environment.borrow().get_at(
|
||||
distance - 1,
|
||||
&Token {
|
||||
token_type: TokenType::This,
|
||||
lexeme: "this".to_owned(),
|
||||
line: 0,
|
||||
},
|
||||
)?;
|
||||
Ok(obj_ref
|
||||
.with_property_carrier(
|
||||
|inst| inst.get_super(itpr_state, &super_expr, distance),
|
||||
|| panic!("'this' didn't contain an instance"),
|
||||
)?
|
||||
.into())
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue