小编Ire*_*app的帖子

我第一次使用Edward Kmett的镜头库,发现它相当不错,但我遇到了麻烦...

[1]中的问题解释了存在量词会破坏makeLenses.我真的很想以某种方式使用带镜片的存在主义.

作为背景,我有课:

class (TextShow file, Eq file, Ord file, Typeable file) => File file where
  fromAnyFile :: AnyFile -> Maybe file
  fileType :: Simple Lens file FileType
  path :: Simple Lens file Text.Text
  provenance :: Simple Lens file Provenance

对于实际问题,我想要的类型:

data AnyFile = forall file . File file => AnyFile { _anyFileAnyFile :: File }

我希望能够写下以下内容:

instance File AnyFile where
  fromAnyFile (AnyFile file) = cast file
  fileType (AnyFile file) = fileType . anyFile
  path (AnyFile file) …

在jquery-mobile中开发webapp时,我遇到了一些奇怪的错误.当我提示警报时,如果我触摸该页面的某些输入,iOS Safari和Chrome将完全冻结,我只能通过任务管理器关闭它们.

如果它是苹果故障或者它是我的,我很困惑.

一些代码:

$('.checkout-comprar-button').click(function(){                 
  alert("hola!!!");
});

这是事件的div:

<div class="grp-bottombar-button checkout-comprar-button" style="width: 50% !important; float: right !important; display: block !important; padding-top: 12px;">
        <span class="green-desplegable grp-bottombar-button-text">
             <? echo _("checkoutcreditcard.seguircompra"); ?>
        </span>
</div>

这是输入之一:

<div class="checkout-datos-numero checkout-first-form checkout-form-field-container">
   <div class="checkout-field">
      <input type="tel" placeholder="<? echo _('creditcard.numero'); ?>" name="" id="checkout-num-tarjeta" maxlength="30" />
   </div>
</div>

显示警报后,如果我想要关注一些输入,浏览器会冻结.当我强制关闭Safari时,这是控制台给我的消息:

<Warning>: MobileSafari[2985] has active assertions beyond permitted time: 
    {(
        <BKProcessAssertion: 0x1e857480> identifier: Suspending process: MobileSafari[2985] permittedBackgroundDuration: 10.000000 reason: suspend owner pid:26 preventSuspend  preventThrottleDownCPU  preventThrottleDownUI 
    )}
<Warning>: Forcing crash report …