Menene currying da karagawa mai wadata?

Question

Accepted Answer

**Currying** yana rua aiki da yayi daɗi N gardafi zuwa sararin N aiki waɗanda kowannensu yayi daɗi daɗi gida. **Karagawa mai wadata** yana tsaita *wasu* gardafi yanzu kuma yana mayar aiki wanda ke jira ragowar.

```js
// normal
const add = (a, b, c) => a + b + c;

// curried — one argument at a time
const curriedAdd = a => b => c => a + b + c;
curriedAdd(1)(2)(3); // 6

// partial application — pre-fill some args
const add10 = curriedAdd(10);   // a is fixed at 10
add10(5)(1);                     // 16
```

Kowannen mataki yana amfani da **closure** don tunawa da gardafin da aka gani jiya har sai duka aka samar.

## Me yake sa ya kasance mai amfani: gina aiki na musamman

```js
const log = level => message => console.log(`[${level}] ${message}`);
const error = log("ERROR");   // reusable, pre-configured logger
const info = log("INFO");
error("disk full");           // [ERROR] disk full
```

A maimakon maimaita matakin a ko'ina, kuna haifar da aiki da aka tsara sau ɗaya. Wannan yana brille a cikin kusawa ta aiki da jerida:

```js
const onChange = field => e => setForm(f => ({ ...f, [field]: e.target.value }));
<input onChange={onChange("email")} />  // a handler specialized to "email"
```

## General curry / yadda ke damje

Yadda ke damje (Ramda, lodash `curry`) auto-curry aiki kowane hanyar da za ku samar da gardafi a cikin ƙungiyoyin jingina.

## Me yake sa ya zama mahimmanci

Currying yana bada damar tsatsi **function composition**, sake amfani da aiki, da style na point-free.

Ya zama gajiya a cikin tushen ma'amala kuma jiya ne an yi bugi-bugi don gwaji fahimtar rufewa.