public Void visitLiteralExpr(Expr.Literal expr)
{
return(null);
}
public object visitLiteralExpr(Expr.Literal expr)
{
return(expr.value);
}
private Stmt ForStatement()
{
Consume(TokenType.LEFT_PAREN, "Expect '(' after for statement.");
Stmt initializer;
if (Match(TokenType.SEMICOLON))
{
initializer = null;
}
else if (Match(TokenType.LET))
{
initializer = LetDeclaration();
}
else
{
initializer = ExpressionStatement();
}
Expr cond = null;
if (!Check(TokenType.SEMICOLON))
{
cond = Expression();
}
Consume(TokenType.SEMICOLON, "Expect ';' after condition in for statement");
Expr increment = null;
if (!Check(TokenType.RIGHT_PAREN))
{
increment = Expression();
}
Consume(TokenType.RIGHT_PAREN, "Expect ')' after for expressions.");
Stmt body = Statement();
if (increment != null)
{
body = new Stmt.Block(new List <Stmt>()
{
body,
new Stmt.Expression(increment)
});
}
if (cond == null)
{
cond = new Expr.Literal(true);
}
body = new Stmt.While(cond, body);
if (initializer != null)
{
body = new Stmt.Block(new List <Stmt>()
{
initializer,
body
});
}
return(body);
}