如何以Typescript 0.9.5编程枚举枚举类型？ [英] How to programmatically enumerate an enum type in Typescript 0.9.5?

问题描述

说我有一个TypeScript枚举，MyEnum，如下所示：

 枚举MyEnum {
首先，
第二，
第三
} 
  

什么是最好的方式TypeScript 0.9.5生成枚举值的数组？示例：

  var choices：MyEnum []; //或Array< MyEnum> 
 choices = MyEnum.GetValues（）; //计划这个？ 
 choices = EnumEx.GetValues（MyEnum）; //或者，怎么滚我自己？ 
  

解决方案

这是该枚举的JavaScript输出： p>

  var MyEnum; 
（function（MyEnum）{
 MyEnum [MyEnum [First] = 0] =First; 
 MyEnum [MyEnum [Second] = 1] =Second 
 MyEnum [MyEnum [Third] = 2] =Third; 
}）（MyEnum ||（MyEnum = {}））; 
  

这是一个像这样的对象：

  Object {
 0：First，
 1：Second，
 2：Third，
 First：0， 
第二：1，
第三：2 
} 
  

strong>成员名称

要获取枚举成员名称，我们可以通过任何是字符串过滤对象的值：

  const objValues = Object.keys（MyEnum）.map（k => MyEnum [k]）; 
 const names = objValues.filter（v => typeof v ===string）as string []; 
  

包含： [First，Second，Third]

会员价值

枚举成员值，我们可以通过是数字的任何东西过滤对象的值：

  const值= objValues.filter（v => typeof v ===number）as number []; 
  

包含： [0，1，2]

扩展类

我认为最好的方法是创建自己的函数（例如 EnumEx.getNames（MyEnum））。您不能向枚举添加一个函数。

  class EnumEx {
 static getNamesAndValues< T extends number>（ e：any）{
 return EnumEx.getNames（e）.map（n =>（{name：n，value：e [n] as T}））; 
} 
 
 static getNames（e：any）{
 return EnumEx.getObjValues（e）.filter（v => typeof v ===string）as string []; 
} 
 
 static getValues< T extends number>（e：any）{
 return EnumEx.getObjValues（e）.filter（v => typeof v ===数字）作为T []; 
} 
 
 private static getObjValues（e：any）：（number | string）[] {
 return Object.keys（e）.map（k => e [ K]）; 
} 
} 
  

Say I have a TypeScript enum, MyEnum, as follows:

enum MyEnum {
    First,
    Second,
    Third
}

What would be the best way in TypeScript 0.9.5 to produce an array of the enum values? Example:

var choices: MyEnum[]; // or Array<MyEnum>
choices = MyEnum.GetValues(); // plans for this?
choices = EnumEx.GetValues(MyEnum); // or, how to roll my own?

解决方案

This is the JavaScript output of that enum:

var MyEnum;
(function (MyEnum) {
    MyEnum[MyEnum["First"] = 0] = "First";
    MyEnum[MyEnum["Second"] = 1] = "Second";
    MyEnum[MyEnum["Third"] = 2] = "Third";
})(MyEnum || (MyEnum = {}));

Which is an object like this:

Object {
    0: "First",
    1: "Second",
    2: "Third",
    First: 0,
    Second: 1,
    Third: 2
}

Member Names

To get the enum member names, we can filter the object's values by anything that is a string:

const objValues = Object.keys(MyEnum).map(k => MyEnum[k]);
const names = objValues.filter(v => typeof v === "string") as string[];

Contains: ["First", "Second", "Third"]

Member Values

While to get the enum member values, we can filter the object's values by anything that is a number:

const values = objValues.filter(v => typeof v === "number") as number[];

Contains: [0, 1, 2]

Extension Class

I think the best way to do this is to create your own functions (ex. EnumEx.getNames(MyEnum)). You can't add a function to an enum.

class EnumEx {
    static getNamesAndValues<T extends number>(e: any) {
        return EnumEx.getNames(e).map(n => ({ name: n, value: e[n] as T }));
    }

    static getNames(e: any) {
        return EnumEx.getObjValues(e).filter(v => typeof v === "string") as string[];
    }

    static getValues<T extends number>(e: any) {
        return EnumEx.getObjValues(e).filter(v => typeof v === "number") as T[];
    }

    private static getObjValues(e: any): (number | string)[] {
        return Object.keys(e).map(k => e[k]);
    }
}

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