Skip to main content

Semigroup

Instances​

Constructors​

Model​

Utilities​

Instances​

first​

Always return the first argument.

Signature​

export declare const first: <A = never>() => Semigroup<A>

Details​

  • Added in 0.1.0

Example​

import * as S from '@fp-tx/core/Semigroup'

assert.deepStrictEqual(S.first<number>().concat(1, 2), 1)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

last​

Always return the last argument.

Signature​

export declare const last: <A = never>() => Semigroup<A>

Details​

  • Added in 0.1.0

Example​

import * as S from '@fp-tx/core/Semigroup'

assert.deepStrictEqual(S.last<number>().concat(1, 2), 2)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Constructors​

constant​

Signature​

export declare const constant: <A>(a: A) => Semigroup<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

max​

Get a semigroup where concat will return the maximum, based on the provided order.

Signature​

export declare const max: <A>(O: Or.Ord<A>) => Semigroup<A>

Details​

  • Added in 0.1.0

Example​

import * as N from '@fp-tx/core/number'
import * as S from '@fp-tx/core/Semigroup'

const S1 = S.max(N.Ord)

assert.deepStrictEqual(S1.concat(1, 2), 2)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

min​

Get a semigroup where concat will return the minimum, based on the provided order.

Signature​

export declare const min: <A>(O: Or.Ord<A>) => Semigroup<A>

Details​

  • Added in 0.1.0

Example​

import * as N from '@fp-tx/core/number'
import * as S from '@fp-tx/core/Semigroup'

const S1 = S.min(N.Ord)

assert.deepStrictEqual(S1.concat(1, 2), 1)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Model​

Semigroup​

Signature​

export interface Semigroup<A> extends Magma<A> {}

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Utilities​

concatAll​

Given a sequence of as, concat them and return the total.

If as is empty, return the provided startWith value.

Signature​

export declare const concatAll: <A>(S: Semigroup<A>) => (startWith: A) => (as: ReadonlyArray<A>) => A

Details​

  • Added in 0.1.0

Example​

import { concatAll } from '@fp-tx/core/Semigroup'
import * as N from '@fp-tx/core/number'

const sum = concatAll(N.SemigroupSum)(0)

assert.deepStrictEqual(sum([1, 2, 3]), 6)
assert.deepStrictEqual(sum([]), 0)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

fold​

Use concatAll instead.

Signature​

export declare function fold<A>(S: Semigroup<A>): {
  (startWith: A): (as: ReadonlyArray<A>) => A
  (startWith: A, as: ReadonlyArray<A>): A
}

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getDualSemigroup​

Use reverse instead.

Signature​

export declare const getDualSemigroup: <A>(S: Semigroup<A>) => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getFirstSemigroup​

Use first instead.

Signature​

export declare const getFirstSemigroup: <A = never>() => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getFunctionSemigroup​

Use getSemigroup instead.

Signature​

export declare const getFunctionSemigroup: <S>(S: Semigroup<S>) => <A = never>() => Semigroup<(a: A) => S>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getIntercalateSemigroup​

Use intercalate instead.

Signature​

export declare const getIntercalateSemigroup: <A>(middle: A) => (S: Semigroup<A>) => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getJoinSemigroup​

Use max instead.

Signature​

export declare const getJoinSemigroup: <A>(O: Or.Ord<A>) => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getLastSemigroup​

Use last instead.

Signature​

export declare const getLastSemigroup: <A = never>() => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getMeetSemigroup​

Use min instead.

Signature​

export declare const getMeetSemigroup: <A>(O: Or.Ord<A>) => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getObjectSemigroup​

Use getAssignSemigroup instead.

Signature​

export declare const getObjectSemigroup: <A extends object = never>() => Semigroup<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getStructSemigroup​

Use struct instead.

Signature​

export declare const getStructSemigroup: <O extends ReadonlyRecord<string, any>>(semigroups: {
  [K in keyof O]: Semigroup<O[K]>
}) => Semigroup<O>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getTupleSemigroup​

Use tuple instead.

Signature​

export declare const getTupleSemigroup: <T extends ReadonlyArray<Semigroup<any>>>(
  ...semigroups: T
) => Semigroup<{
  [K in keyof T]: T[K] extends Semigroup<infer A> ? A : never
}>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

intercalate​

Between each pair of elements insert middle.

Signature​

export declare const intercalate: <A>(middle: A) => (S: Semigroup<A>) => Semigroup<A>

Details​

  • Added in 0.1.0

Example​

import { intercalate } from '@fp-tx/core/Semigroup'
import * as S from '@fp-tx/core/string'
import { pipe } from '@fp-tx/core/function'

const S1 = pipe(S.Semigroup, intercalate(' + '))

assert.strictEqual(S1.concat('a', 'b'), 'a + b')

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

reverse​

The dual of a Semigroup, obtained by swapping the arguments of concat.

Signature​

export declare const reverse: <A>(S: Semigroup<A>) => Semigroup<A>

Details​

  • Added in 0.1.0

Example​

import { reverse } from '@fp-tx/core/Semigroup'
import * as S from '@fp-tx/core/string'

assert.deepStrictEqual(reverse(S.Semigroup).concat('a', 'b'), 'ba')

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

semigroupAll​

Use SemigroupAll instead.

Signature​

export declare const semigroupAll: Semigroup<boolean>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

semigroupAny​

Use SemigroupAny instead.

Signature​

export declare const semigroupAny: Semigroup<boolean>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

semigroupProduct​

Use SemigroupProduct instead.

Signature​

export declare const semigroupProduct: Semigroup<number>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

semigroupString​

Use Semigroup instead.

Signature​

export declare const semigroupString: Semigroup<string>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

semigroupSum​

Use SemigroupSum instead.

Signature​

export declare const semigroupSum: Semigroup<number>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

semigroupVoid​

Use void module instead.

Signature​

export declare const semigroupVoid: Semigroup<void>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

struct​

Given a struct of semigroups returns a semigroup for the struct.

Signature​

export declare const struct: <A>(semigroups: { [K in keyof A]: Semigroup<A[K]> }) => Semigroup<{
  readonly [K_1 in keyof A]: A[K_1]
}>

Details​

  • Added in 0.1.0

Example​

import { struct } from '@fp-tx/core/Semigroup'
import * as N from '@fp-tx/core/number'

interface Point {
  readonly x: number
  readonly y: number
}

const S = struct<Point>({
  x: N.SemigroupSum,
  y: N.SemigroupSum,
})

assert.deepStrictEqual(S.concat({ x: 1, y: 2 }, { x: 3, y: 4 }), { x: 4, y: 6 })

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

tuple​

Given a tuple of semigroups returns a semigroup for the tuple.

Signature​

export declare const tuple: <A extends readonly unknown[]>(
  ...semigroups: { [K in keyof A]: Semigroup<A[K]> }
) => Semigroup<Readonly<A>>

Details​

  • Added in 0.1.0

Example​

import { tuple } from '@fp-tx/core/Semigroup'
import * as B from '@fp-tx/core/boolean'
import * as N from '@fp-tx/core/number'
import * as S from '@fp-tx/core/string'

const S1 = tuple(S.Semigroup, N.SemigroupSum)
assert.deepStrictEqual(S1.concat(['a', 1], ['b', 2]), ['ab', 3])

const S2 = tuple(S.Semigroup, N.SemigroupSum, B.SemigroupAll)
assert.deepStrictEqual(S2.concat(['a', 1, true], ['b', 2, false]), ['ab', 3, false])

License​

  • MIT – Copyright (c) 2017-present Giulio Canti