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macoolka-typescript

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概述

Common Type

目录

Endomorphism (接口)

形变

签名

interface Endomorphism {}

v0.2.0 中添加

FunctionN (接口)

签名

interface FunctionN {}

示例

import { FunctionN } from 'macoolka-typescript'

export const sum: FunctionN<[number, number], number> = (a, b) => a + b

v0.2.0 中添加

Lazy (接口)

延迟的对象

签名

interface Lazy {}

v0.2.0 中添加

NonEmptyArray (接口)

非空数组

签名

interface NonEmptyArray extends Array, Array, Array, Array, Array, Array {
  0: A
}

示例

import { NonEmptyArray } from 'macoolka-typescript'

type A = { a: string; b: number }
type Result = NonEmptyArray<A>
const result1: Result = [{ b: 1 }] //correct
const result3: Result = [] //error

v0.2.0 中添加

Predicate (接口)

断言

签名

interface Predicate {}

v0.2.0 中添加

Refinement (接口)

断言类型 A 是 B

签名

interface Refinement {}

v0.2.0 中添加

AnyTuple (类型)

签名

export type AnyTuple = Array<any> & { '0': any }

示例

import { AnyTuple } from 'macoolka-typescript'

declare function f<T extends AnyTuple>(x: T): T
declare const x: [number]
declare const y: [number, string]
declare const z: [number, string, boolean]
f(x)
f(y)
f(z)
// $ExpectError
// f([1, 2, 3])

v0.2.0 中添加

AtLeastOne (类型)

约束类型至少有一个属性

签名

export type AtLeastOne<T, U = { [K in keyof T]: Pick<T, K> }> = Partial<T> & U[keyof U]

示例

import { AtLeastOne } from 'macoolka-typescript'

type A = { a: string; b: number }
type Result = AtLeastOne<A>
const result: Result = { a: '' } //correct
const result1: Result = { b: 1 } //correct
const result2: Result = { a: '', b: 1 } //correct
const result3: Result = {} //error

v0.2.0 中添加

DeepReadonly (类型)

设置所有的成员为readonly

签名

export type DeepReadonly<A> = A extends Array<infer B> ? DeepReadonlyArray<B> : DeepReadonlyObject<A>

示例

import { DeepReadonly } from 'macoolka-typescript'

interface Foo {
  bar: {
    baz: string
    quux: Array<{ barbaz: number }>
  }
}

type ReadonlyFoo = DeepReadonly<Foo>
export declare const x: ReadonlyFoo
// $ExpectError
// x.bar.quux[1].barbaz = 1

v0.2.0 中添加

Diff (类型)

定义一些属性为Partial

签名

export type Diff<A extends object, OK extends keyof A> = Compact<
  { [K in Exclude<keyof A, OK>]: A[K] } & { [K in OK]?: A[K] }
>

示例

import { Diff } from 'macoolka-typescript'

export type Result = Diff<{ a: string; b: number }, 'b'> // { a: string; b?: number }

v0.2.0 中添加

Equals (类型)

判断两个类型是否相等

签名

export type Equals<A, B> = (<C>() => C extends Compact<A> ? 'T' : 'F') extends (<C>() => C extends Compact<B>
  ? 'T'
  : 'F')
  ? 'T'
  : 'F'

示例

import { Equals } from 'macoolka-typescript'

export type Result1 = Equals<string, string> // "T"
export type Result2 = Equals<string, number> // "F"

v0.2.0 中添加

Exact (类型)

排除一个类型的所有成员

签名

export type Exact<A extends object, B extends A> = A & Record<Exclude<keyof B, keyof A>, never>

示例

import { Exact } from 'macoolka-typescript'

declare function f<T extends Exact<{ a: string }, T>>(a: T): void
f({ a: 'a' })
// $ExpectError
// f({ a: 'a', b: 1 })

v0.2.0 中添加

KeysOfNotType (类型)

获取非特定类型的key

签名

export type KeysOfNotType<A extends object, B> = { [K in keyof A]-?: A[K] extends B ? never : K }[keyof A]

示例

import { KeysOfType } from 'macoolka-typescript'

export type Result = KeysOfNotType<{ a: string; b: string | boolean; c: boolean; d: string }, string> // "b" | "c"

v0.2.0 中添加

KeysOfType (类型)

获取特定类型的key

签名

export type KeysOfType<A extends object, B> = { [K in keyof A]-?: A[K] extends B ? K : never }[keyof A]

示例

import { KeysOfType } from 'macoolka-typescript'

export type Result = KeysOfType<{ a: string; b: string | boolean; c: boolean; d: string }, string> // "a" | "d"

v0.2.0 中添加

Maybe (类型)

类型可以为空

签名

export type Maybe<T> = null | undefined | T

v0.2.0 中添加

OptionalKeys (类型)

得到可选的key

签名

export type OptionalKeys<T> = { [K in keyof T]: T extends Record<K, T[K]> ? never : K } extends {
  [_ in keyof T]: infer U
}
  ? {} extends U
    ? never
    : U
  : never

示例

import { OptionalKeys } from 'macoolka-typescript'

type A = { a: string; b: number; x?: string; y?: number }
export type Result = OptionalKeys<A> // "x" | "y"

v0.2.0 中添加

Overwrite (类型)

用一个类型覆盖另一个类型

签名

export type Overwrite<A extends object, B extends object> = Compact<{ [K in Exclude<keyof A, keyof B>]: A[K] } & B>

示例

import { Overwrite } from 'macoolka-typescript'

export type Result = Overwrite<{ a: string; b: number }, { b: boolean }> // { a: string; b: boolean }

v0.2.0 中添加

PredicateWithIndex (类型)

断言一个索引类型

签名

export type PredicateWithIndex<I, A> = (i: I, a: A) => boolean

v0.2.0 中添加

PredicateWithOptionIndex (类型)

断言一个可选索引类型

签名

export type PredicateWithOptionIndex<I, A> = (a: A, i?: I) => boolean

v0.2.0 中添加

RefinementWithIndex (类型)

断言一个索引类型 A 是 B

签名

export type RefinementWithIndex<I, A, B extends A> = (i: I, a: A) => a is B

v0.2.0 中添加

RefinementWithOptionIndex (类型)

断言一个可选索引类型 A 是 B

签名

export type RefinementWithOptionIndex<I, A, B extends A> = (a: A, i?: I) => a is B

v0.2.0 中添加

RequiredKeys (类型)

得到必填的key

签名

export type RequiredKeys<T> = { [K in keyof T]: {} extends Pick<T, K> ? never : K } extends { [_ in keyof T]: infer U }
  ? {} extends U
    ? never
    : U
  : never

示例

import { RequiredKeys } from 'macoolka-typescript'

type A = { a: string; b: number; x?: string; y?: number }
export type Result = RequiredKeys<A> // "a" | "b"

v0.2.0 中添加

RowLacks (类型)

约束不包括指定的key

签名

export type RowLacks<A extends object, K extends string | number | symbol> = A & Record<Extract<keyof A, K>, never>

示例

import { RowLacks } from 'macoolka-typescript'

export declare function f(x: RowLacks<{ a: string; b: number }, 'a' | 'b'>): void
// $ExpectError
// f({ a: 'a', b: 1 })
declare function g(x: RowLacks<{ a: string; b: number }, 'c'>): void
g({ a: 'a', b: 1 }) // ok

v0.2.0 中添加

TaggedUnionMember (类型)

获取特定的类型通过标记

签名

export type TaggedUnionMember<A extends object, Tag extends keyof A, Value extends A[Tag]> = Extract<
  A,
  Record<Tag, Value>
>

示例

import { TaggedUnionMember } from 'macoolka-typescript'

type A = { tag: 'A'; a: string }
type B = { tag: 'B'; b: number }
type C = A | B
export type Result = TaggedUnionMember<C, 'tag', 'A'> // A

v0.2.0 中添加