private Stmt ForStatement()
{
Consume(TokenType.LeftParen, "Expect '(' after 'for'.");
Stmt initializer;
if (Match(TokenType.Semicolon))
{
// None is defined
initializer = null;
}
else if (Match(TokenType.Var))
{
initializer = VarDeclartion();
}
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.RightParen))
{
increment = Expression();
}
Consume(TokenType.RightParen, "Expect ')' after for clauses.");
Exception exception = null;
try
{
m_LoopDepth++;
Stmt body = Statement();
if (increment != null)
{
Stmt.Expression expression = new Stmt.Expression(increment);
List <Stmt> content = new List <Stmt>()
{
body, expression
};
body = new Stmt.Block(content);
}
if (condition == null)
{
condition = new Expr.Literal(true);
}
body = new Stmt.While(condition, body);
if (initializer != null)
{
List <Stmt> content = new List <Stmt>()
{
initializer, body
};
body = new Stmt.Block(content);
}
return(body);
}
catch (Exception e)
{
exception = e;
}
finally
{
m_LoopDepth--;
}
throw exception;
}
public object Visit(Stmt.While _while)
{
Resolve(_while.condition);
Resolve(_while.body);
return(null);
}