feat: 17

questions/14-easy-head/README.md

@@ -5,7 +5,7 @@ Implement a generic `Head<T>` that takes an Array `T` and returns it's first ele
 
 For example
 
-```
+```ts
 type arr1 = ['a', 'b', 'c']
 type arr2 = [3, 2, 1]
 

questions/15-medium-tail/README.md

@@ -1,12 +1,12 @@
 <!--info-header-start--><h1>Tail of Array <img src="https://img.shields.io/badge/-medium-eaa648" alt="medium"/> <img src="https://img.shields.io/badge/-%23array-999" alt="#array"/> <img src="https://img.shields.io/badge/-%234.0-999" alt="#4.0"/></h1><blockquote><p>by Anthony Fu <a href="https://github.com/antfu" target="_blank">@antfu</a></p></blockquote><p><a href="https://type-challenges.netlify.app/15/play" target="_blank"><img src="https://img.shields.io/badge/-Take%20the%20Challenge-3178c6?logo=typescript" alt="Take the Challenge"/></a> </p><!--info-header-end-->
 
-> TypeScript 4.0 is Recommended in this challenge
+> TypeScript 4.0 is recommended in this challenge
 
 Implement a generic `Tail<T>` that takes an Array `T` and returns it's last element's type.
 
 For example
 
-```
+```ts
 type arr1 = ['a', 'b', 'c']
 type arr2 = [3, 2, 1]
 

questions/16-medium-pop/README.md

@@ -1,12 +1,12 @@
 <!--info-header-start--><h1>Pop <img src="https://img.shields.io/badge/-medium-eaa648" alt="medium"/> <img src="https://img.shields.io/badge/-%23array-999" alt="#array"/> <img src="https://img.shields.io/badge/-%234.0-999" alt="#4.0"/></h1><blockquote><p>by Anthony Fu <a href="https://github.com/antfu" target="_blank">@antfu</a></p></blockquote><p><a href="https://type-challenges.netlify.app/16/play" target="_blank"><img src="https://img.shields.io/badge/-Take%20the%20Challenge-3178c6?logo=typescript" alt="Take the Challenge"/></a> </p><!--info-header-end-->
 
-> TypeScript 4.0 is Recommended in this challenge
+> TypeScript 4.0 is recommended in this challenge
 
 Implement a generic `Pop<T>` that takes an Array `T` and returns an Array without it's last element.
 
 For example
 
-```
+```ts
 type arr1 = ['a', 'b', 'c', 'd']
 type arr2 = [3, 2, 1]
 

questions/17-hard-currying-1/README.md

@@ -0,0 +1,24 @@
+<!--info-header-start--><h1>Currying 1 <img src="https://img.shields.io/badge/-hard-red" alt="hard"/> <img src="https://img.shields.io/badge/-%23array-999" alt="#array"/> <img src="https://img.shields.io/badge/-%234.0-999" alt="#4.0"/></h1><blockquote><p>by Anthony Fu <a href="https://github.com/antfu" target="_blank">@antfu</a></p></blockquote><p><a href="https://type-challenges.netlify.app/17/play" target="_blank"><img src="https://img.shields.io/badge/-Take%20the%20Challenge-3178c6?logo=typescript" alt="Take the Challenge"/></a> </p><!--info-header-end-->
+
+> TypeScript 4.0 is recommended in this challenge
+
+[Currying](https://en.wikipedia.org/wiki/Currying) is the technique of converting a function that takes multiple arguments into a sequence of functions that each take a single argument. 
+
+For example:
+
+```ts
+const add = (a: number, b: number) => a + b
+const three = add(1, 2)
+
+const curriedAdd = Currying(add)
+const five = curriedAdd(2)(3)
+```
+
+The function passed to `Currying` may have multiple arguments, you need to correctly type it.
+
+In this challenge, the curried function only accept one argument at a time. Once all the argument is assigned, it should return its result.
+
+
+**Extra**: Similarly, can you implement `Shift`, `Push` and `Unshift` as well?
+
+<!--info-footer-start--><br><a href="../../README.md" target="_blank"><img src="https://img.shields.io/badge/-Back-grey" alt="Back"/></a> <a href="https://type-challenges.netlify.app/17/solutions" target="_blank"><img src="https://img.shields.io/badge/-Check%20out%20Solutions-de5a77?logo=awesome-lists&logoColor=white" alt="Check out Solutions"/></a> <a href="https://type-challenges.netlify.app/17/answer" target="_blank"><img src="https://img.shields.io/badge/-Share%20your%20Solutions-green" alt="Share your Solutions"/></a> <!--info-footer-end-->

questions/17-hard-currying-1/info.yml

@@ -0,0 +1,13 @@
+title: Currying 1
+
+author:
+  name: Anthony Fu
+  email: hi@antfu.me
+  github: antfu
+
+tags: array, 4.0
+
+tsconfig: 
+  ts: 4.0.0-beta
+
+related: 14, 16

questions/17-hard-currying-1/info.zh-CN.yml

@@ -0,0 +1 @@
+title: 科里化 1

questions/17-hard-currying-1/template.ts

@@ -0,0 +1 @@
+declare function Currying(fn: any): any

questions/17-hard-currying-1/test-cases.ts

@@ -0,0 +1,13 @@
+import { Equal, Expect } from '@type-challenges/utils'
+
+const curried1 = Currying((a: string, b: number, c: boolean) => true)
+const curried2 = Currying((a: string, b: number, c: boolean, d: boolean, e: boolean, f: string, g: boolean) => true)
+
+type cases = [
+  Expect<Equal<
+    typeof curried1, (a: string) => (b: number) => (c: boolean) => boolean
+  >>,
+  Expect<Equal<
+    typeof curried2, (a: string) => (b: number) => (c: boolean) => (d: boolean) => (e: boolean) => (f: string) => (g: boolean) => boolean
+  >>,
+]