Question

我一直在尝试使用函数式编程，而我正试图绕过部分应用程序和currying。

我正在寻找一些有关如何将部分应用和 currying 应用于以下功能的见解：

var Page_Validators = [{
  "controltovalidate": "Content_C002_txtAddress",
  "focusOnError": "t",
  "errormessage": "No Address Entered",
  "display": "Dynamic",
  "validationGroup": "ProfileControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_txtCity",
  "focusOnError": "t",
  "errormessage": "No City Entered",
  "display": "Dynamic",
  "validationGroup": "ProfileControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_drpState",
  "focusOnError": "t",
  "errormessage": "State Required",
  "display": "Dynamic",
  "validationGroup": "ProfileControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_txtZipcode",
  "focusOnError": "t",
  "errormessage": "No Zipcode Entered",
  "display": "Dynamic",
  "validationGroup": "ProfileControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_phoneNumberFull",
  "focusOnError": "t",
  "errormessage": "Missing Phone Number",
  "display": "Dynamic",
  "validationGroup": "ProfileControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_txtSupFullName",
  "focusOnError": "t",
  "errormessage": "No Name Entered",
  "display": "Dynamic",
  "validationGroup": "SupervisorControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_txtSupTitle",
  "focusOnError": "t",
  "errormessage": "No Title Entered",
  "display": "Dynamic",
  "validationGroup": "SupervisorControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_txtSupPhoneFull",
  "focusOnError": "t",
  "errormessage": "Missing Phone Number",
  "display": "Dynamic",
  "validationGroup": "SupervisorControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_txtSupEmail",
  "focusOnError": "t",
  "errormessage": "No Email Entered",
  "display": "Dynamic",
  "validationGroup": "SupervisorControl",
  "initialvalue": "",
  "isvalid": true
}, {
  "controltovalidate": "Content_C002_SignatureField",
  "focusOnError": "t",
  "errormessage": "Signature Required",
  "display": "Dynamic",
  "validationGroup": "ProfileControl",
  "initialvalue": "",
  "isvalid": true
}];


function filterArrayBy(arr, searchString) {
  return arr.filter(key => key.controltovalidate.toLowerCase().includes(searchString.toLowerCase()));
}

function toggleValidatorsState(arr, condtion) {
  return arr.map(el => ValidatorEnable(el, condition));
}

const supervisorValidators = filterArrayBy(Page_Validators, "txtSup");
const disabledValidators = toggleValidatorsState(supervisorValidators, true);

console.log(disabledValidators);

ASIDE

toggleValidatorState函数正在调用ASP.NET函数，因此代码片段不起作用（除非你有asp.net）

除了ASP.NET函数之外，可以简化这些函数还是使用curry部分应用程序？

我觉得我必须通过将数组传递给两个函数来重复自己。

我一直在研究使用Lodash或Ramda但是如果不使用外部库我可以实现相同的目标。

Answer 1

这可能是一种过度杀伤，因为代码看起来很简单。

但你可以通过将filterArayBy绑定到Page_Validators来讨好disableValidators。因此，您可以通过不同的searchStrings对其进行过滤，而无需每次都传递数组。

此外，您可以通过toggleValidatorsState部分应用condition = true来制作名为.bind的新功能。

实现这一目标的最简单方法是使用function filterArrayBy(arr, searchString) { return arr.filter(key => key.controltovalidate.toLowerCase().includes(searchString.toLowerCase())); } // We are going to partially apply filterArrayBy function as the first argument is going to be the same. // (in this context partial application does the same as currying) const filterPageValidators = filterArrayBy.bind(null, Page_Validators); function toggleValidatorsState(arr, condtion) { return arr.map(el => ValidatorEnable(el, condition)); } // Also partially applying toggleValidatorsState to make the code more readable const disableValidators = arr => toggleValidatorsState(arr, true); // The usage would look like this const disabledValidators = disableValidators(filterPageValidators('txtSup'));和这样的简单lambda：

curry

如果您想让它更复杂，可以查看this article实施您自己的filterPageValidators方法并使用它来制作partialRight。

然后你需要类似于Ramda的const filterPageValidators = curry(filterArrayBy)(Page_Validators); const disableValidators = bind_trailing_args(toggleValidatorsState, true);。因此，您可以使用this answer作为参考。

最后，你的功能看起来像这样：

    LocalDate date = LocalDate.of(2018, Month.MAY, 31);
    date = date.with(Month.FEBRUARY);
    System.out.println(date.getMonth());
    System.out.println(date);

但在我看来，对于这个特殊情况来说，这实在太多了。

没有lodash咖喱我的功能

1 个答案: