D (Dict)

Dict<A> is Record<string, A>.

Non-dual

keys<A>(d: Dict<A>): string[]
values<A>(d: Dict<A>): A[]
toEntries<A>(d: Dict<A>): [string, A][]
fromEntries<A>(entries: [string, A][]): Dict<A>
isEmpty<A>(d: Dict<A>): boolean

Dual

get<A>(d: Dict<A>, key: string): A | undefined
map<A, B>(d: Dict<A>, f: (a: A, key: string) => B): Dict<B>
filter<A>(d: Dict<A>, pred: (a: A, key: string) => boolean): Dict<A>
merge<A>(a: Dict<A>, b: Dict<A>): Dict<A>

Examples

import { pipe, A, D } from '@stopcock/fp'

// count items per category
const counts = pipe(
  A.groupBy(products, p => p.category),
  D.map(items => items.length),
)
// { electronics: 12, clothing: 8 }

// merge config layers
const config = pipe(
  defaults,
  D.merge(envOverrides),
  D.merge(cliFlags),
)

// filter out empty groups
pipe(
  grouped,
  D.filter(items => items.length > 0),
)

// build lookup table
const byId = D.fromEntries(
  users.map(u => [u.id, u]),
)