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 Statements.Block(new List <Stmt>()
{
body, new Statements.Expression(increment)
});
}
if (condition == null)
{
condition = new Expressions.Literal(true);
}
body = new Statements.While(condition, body);
if (initializer != null)
{
body = new Statements.Block(new List <Stmt>()
{
initializer, body
});
}
return(body);
}
object Expressions.IVisitor <object> .VisitLiteralExpr(Expressions.Literal expr)
{
return(null);
}