问题描述
问题: 我发现@ types / lodash方法首先没有涵盖输入是两个(多个)类型数组的并集的情况: //在我的档案中 从'lodash'导入*作为_;
interface First {
name: string;
}
interface Second {
age: number;
}
function performSomeLogic(): First[] | Second[] {
if (Math.random() > 0.5) return [{name: 'Alice'},{name: 'Bob'}];
return [{age: 42},{age: 33}];
}
// we got some array First or Second of type. ok
const returnedData = performSomeLogic(); // we got some array First or Second of type. ok
// we expect value is First or Second of type. NOT ok.
// *******************
// TS ERROR
// TS2345: Argument of type 'First[] | Second[]' is not assignable to
// parameter of type 'ArrayLike<First>'.
// *******************
const firstValueOfData = _.first(returnedData);
// further steps Could be ..
const proceedWithValueOfData = (value: First | Second) => Object.keys(value);
proceedWithValueOfData(firstValueOfData);
想法: 我为 _。first()设计了正确的界面。我尝试将其放入types.d.ts中,将其用于捆绑器:
// typings.d.ts
type DeriveArrTypes<T> = T extends (infer R)[] ? R : T;
// So DeriveArrTypes<First[] | Second[]> returns First|Second union
declare module 'lodash' {
// LoDashStatic IS THE INTERFACE LODASH HAS HAD. FirsT IS DECLARED IN IT. I WANT TO ADD ITS EXTENDED DECLaraTION
interface LoDashStatic {
first<T extends []>(value: T): DeriveArrTypes<T> | undefined;
}
}
成功-否: 但这是行不通的。 Typescript停止显示任何错误(包括其他错误)。我将WebStorm用作IDE,它将继续突出显示。
ENV: 这是一个前端项目,由Typescript服务进行转译,并由Webpack服务进行捆绑(由于其长期持续的生命力:)。 来自 webpack.config.js :
// the rule for ts
{
test: /\.ts$/,use: [{
loader: 'ts-loader',options: {
// disable type checker - we will use it in fork plugin
transpileOnly: true
}
}],},// plugins section
plugins: [
// bla-bla plugins
...
new ForkTsCheckerWebpackPlugin({
tsconfig: __dirname + '/tsconfig.json'
})
]
来自 tsconfig.json :
"compilerOptions": {
// bla-bla options
...
"typeRoots": [
"node_modules/@types"
],}
// I ADDED THIS
"include": [
"app/typings/**/*"
],
当我创建 app / typings 目录并将 typings.d.ts 放入其中时。
解决方法
如果要将接口添加到npm模块,则可以使用>>> from sympy import symbols
>>> from sympy.plotting import plot
>>> x = symbols('x')
>>> p1 = plot(x**4,(x,10,20),label='$x^4$',show=False,legend=True)
>>> p2 = plot(x,line_color='red',label='$x$',legend= True)
>>> p1.extend(p2)
>>> p1.show()
关键字
_backend