17 - Currying 1

[antfu]

✍️ Answers

Name your title starting with the question no you are trying to answer.

For example:
12 - my one-line solution

type Unshift<T> = T extends [infer K, ...infer U] ? U : unknown
type Head<T> = T extends [infer K, ...infer U] ? K : unknown

type Curried<T, R> = T extends Array<any>
  ? T['length'] extends 1
    ? (args: Head<T>) => R
    : (args: Head<T>) => Curried<Unshift<T>, R>
  : never

declare function Currying<T extends unknown[], R>(fn: (...args: T) => R): Curried<T, R>

[suddenlyGiovanni]

A VariadicCurrying would also be a crazy good challenge, plus would also set up a good example on how to approach such a challenge after the introduction of Variadic Tuple types in TS >= 4.0

[millsp]

This implementation is variadic, what did you mean @suddenlyGiovanni? Did you mean that it can take rest args?

[Luncher]

This implementation can't pass the test case

[action-hong]

can not pass the test case

// const curried1: (args: string) => (args: number) => (args: boolean) => boolean
const curried1 = Currying((a: string, b: number, c: boolean) => true)
//const curried2: (args: string) => (args: number) => (args: boolean) => (args: boolean) => (args: boolean) => (args: string) => (args: boolean) => boolean
const curried2 = Currying((a: string, b: number, c: boolean, d: boolean, e: boolean, f: string, g: boolean) => true)

all return boolean instead of true， how to fix it ?