private Stmt forStatement()
{
consume(TokenType.LEFT_PAREN, "Expect '(' after 'for'.");
Stmt initializer;
if (match(TokenType.SEMICOLON))
{
initializer = null;
}
else if (match(TokenType.VAR))
{
initializer = varDeclaration();
}
else
{
initializer = expressionStatement();
}
Expr condition = null;
if (!check(TokenType.SEMICOLON))
{
condition = expression();
}
consume(TokenType.SEMICOLON, "Expect ';' after loop condition.");
Expr increment = null;
if (!check(TokenType.RIGHT_PAREN))
{
increment = expression();
}
consume(TokenType.RIGHT_PAREN, "Expect ')' after 'for' clauses.");
Stmt body = statement();
if (increment != null)
{
body = new Stmt.Block(new List <Stmt> {
body, new Stmt.Expression(increment)
});
}
if (condition == null)
{
condition = new Expr.Literal(TokenType.TRUE);
}
body = new Stmt.While(condition, body);
if (initializer != null)
{
body = new Stmt.Block(new List <Stmt> {
initializer, body
});
}
return(body);
}
public Unit visitBlockStmt(Stmt.Block stmt)
{
executeBlock(stmt.statements, new Environment(environment));
return(Unit.value);
}