CFP - Docs - mPick

mPick

(keys: EntryKey[]) => (collection: EntryCollection) => collection

Pick entries from a collection by key

Consider pick instead.
This is for the uncommon case where mutating collection is required.

Try It

const obj = { a: 1, b: 2, c: 3, d: 4 }
const pickAC = mPick(['a', 'c'])
const mutatedObj = pickAC(obj)
console.log(mutatedObj === obj) // is true
console.log(obj) // is { a: 1, c: 3 }
const obj = { a: 1, b: 2, c: 3, d: 4 }
const pickAC = mPick(['a', 'c'])
const mutatedObj = pickAC(obj)
console.log(mutatedObj === obj) // is true
console.log(obj) // is { a: 1, c: 3 }

Try It

const obj = { a: 1, b: 2, c: 3, d: 4 }
const pickAC = mPick(['a', 'c'])
const mutatedObj = pickAC(obj)
console.log(mutatedObj === obj) // is true
console.log(obj) // is { a: 1, c: 3 }
const obj = { a: 1, b: 2, c: 3, d: 4 }
const pickAC = mPick(['a', 'c'])
const mutatedObj = pickAC(obj)
console.log(mutatedObj === obj) // is true
console.log(obj) // is { a: 1, c: 3 }

Sometimes we want to pick entries by key. Below, we run a cat shelter. A visitor, Grace, is adopting Bella and Leo. Let's get the cats' information to send Grace off with a copy.

Try It

const cats = {
  bella: {
    age: 3,
    notes: 'likes her alone time',
    breed: 'domestic shorthair',
  },
  leo: {
    age: 2,
    notes: 'enjoys food too much',
    breed: 'domestic longhair',
  },
  molly: {
    age: 4,
    notes: 'energetic in the morning',
    breed: 'domestic shorthair',
  },
}

const catsToAdopt = ['bella', 'leo']
const adoptBellaAndLeo = mPick(catsToAdopt)
adoptBellaAndLeo(cats)

console.log(cats)
// is {
//   bella: {
//     age: 3
//     notes: likes her alone time
//     breed: domestic shorthair
//   }
//   leo: {
//     age: 2
//     notes: enjoys food too much
//     breed: domestic longhair
//   }
// }
type Cat = {
  age: number
  notes: string
  breed: string
}
type Cats = Record<string, Cat>
const cats: Cats = {
  bella: {
    age: 3,
    notes: 'likes her alone time',
    breed: 'domestic shorthair',
  },
  leo: {
    age: 2,
    notes: 'enjoys food too much',
    breed: 'domestic longhair',
  },
  molly: {
    age: 4,
    notes: 'energetic in the morning',
    breed: 'domestic shorthair',
  },
}

const catsToAdopt = ['bella', 'leo']
const adoptBellaAndLeo = mPick(catsToAdopt)<Cats>
adoptBellaAndLeo(cats)

console.log(cats)
// is {
//   bella: {
//     age: 3
//     notes: likes her alone time
//     breed: domestic shorthair
//   }
//   leo: {
//     age: 2
//     notes: enjoys food too much
//     breed: domestic longhair
//   }
// }

Try It

const cats = {
  bella: {
    age: 3,
    notes: 'likes her alone time',
    breed: 'domestic shorthair',
  },
  leo: {
    age: 2,
    notes: 'enjoys food too much',
    breed: 'domestic longhair',
  },
  molly: {
    age: 4,
    notes: 'energetic in the morning',
    breed: 'domestic shorthair',
  },
}

const catsToAdopt = ['bella', 'leo']
const adoptBellaAndLeo = mPick(catsToAdopt)
adoptBellaAndLeo(cats)

console.log(cats)
// is {
//   bella: {
//     age: 3
//     notes: likes her alone time
//     breed: domestic shorthair
//   }
//   leo: {
//     age: 2
//     notes: enjoys food too much
//     breed: domestic longhair
//   }
// }
type Cat = {
  age: number
  notes: string
  breed: string
}
type Cats = Record<string, Cat>
const cats: Cats = {
  bella: {
    age: 3,
    notes: 'likes her alone time',
    breed: 'domestic shorthair',
  },
  leo: {
    age: 2,
    notes: 'enjoys food too much',
    breed: 'domestic longhair',
  },
  molly: {
    age: 4,
    notes: 'energetic in the morning',
    breed: 'domestic shorthair',
  },
}

const catsToAdopt = ['bella', 'leo']
const adoptBellaAndLeo = mPick(catsToAdopt)<Cats>
adoptBellaAndLeo(cats)

console.log(cats)
// is {
//   bella: {
//     age: 3
//     notes: likes her alone time
//     breed: domestic shorthair
//   }
//   leo: {
//     age: 2
//     notes: enjoys food too much
//     breed: domestic longhair
//   }
// }