public object VisitWhileStmt(While stmt)
{
LoopType enclosingLoop = currentLoop;
currentLoop = LoopType.WHILE;
Resolve(stmt.Condition);
Resolve(stmt.Body);
currentLoop = enclosingLoop;
return(null);
}
public object VisitWhileStmt(While stmt)
{
while (IsTruthy(Evaluate(stmt.Condition)))
{
try
{
Execute(stmt.Body);
}
catch (BreakException)
{
break;
}
}
return(null);
}
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 Block(new List <Stmt>
{
body,
new Expression(increment)
});
}
if (condition == null)
{
condition = new Literal(true);
}
body = new While(condition, body);
if (initializer != null)
{
body = new Block(new List <Stmt>
{
initializer,
body
});
}
return(body);
}