Monoid overview
Added in v1.0.0
Table of contents
combinators
array
Given a type A, this function creates and returns a Semigroup for ReadonlyArray<A>.
The empty value is the empty array.
Signature
export declare const array: <A>() => Monoid<readonly A[]>
Added in v1.0.0
reverse
The dual of a Monoid, obtained by swapping the arguments of combine.
Signature
export declare const reverse: <A>(M: Monoid<A>) => Monoid<A>
Added in v1.0.0
struct
This function creates and returns a new Monoid for a struct of values based on the given Monoids for each property in the struct. The returned Monoid combines two structs of the same type by applying the corresponding Monoid passed as arguments to each property in the struct.
The empty value of the returned Monoid is a struct where each property is the empty value of the corresponding Monoid in the input monoids object.
It is useful when you need to combine two structs of the same type and you have a specific way of combining each property of the struct.
Signature
export declare const struct: <R extends { readonly [x: string]: Monoid<any> }>(
fields: R
) => Monoid<{ readonly [K in keyof R]: [R[K]] extends [Monoid<infer A>] ? A : never }>
Added in v1.0.0
tuple
Similar to Promise.all but operates on Monoids.
[Monoid<A>, Monoid<B>, ...] -> Monoid<[A, B, ...]>
This function creates and returns a new Monoid for a tuple of values based on the given Monoids for each element in the tuple. The returned Monoid combines two tuples of the same type by applying the corresponding Monoid passed as arguments to each element in the tuple.
The empty value of the returned Monoid is the tuple of empty values of the input Monoids.
It is useful when you need to combine two tuples of the same type and you have a specific way of combining each element of the tuple.
Signature
export declare const tuple: <T extends readonly Monoid<any>[]>(
...elements: T
) => Monoid<{ readonly [I in keyof T]: [T[I]] extends [Monoid<infer A>] ? A : never }>
Added in v1.0.0
constructors
fromSemigroup
Signature
export declare const fromSemigroup: <A>(S: Semigroup<A>, empty: A) => Monoid<A>
Added in v1.0.0
max
Get a monoid where combine will return the maximum, based on the provided bounded order.
The empty value is the minimum value.
Signature
export declare const max: <A>(B: Bounded<A>) => Monoid<A>
Added in v1.0.0
min
Get a monoid where combine will return the minimum, based on the provided bounded order.
The empty value is the maxBound value.
Signature
export declare const min: <A>(B: Bounded<A>) => Monoid<A>
Added in v1.0.0
instances
bigintMultiply
bigint monoid under multiplication.
The empty value is 1n.
Signature
export declare const bigintMultiply: Monoid<bigint>
Added in v1.0.0
bigintSum
number monoid under addition.
The bigint value is 0n.
Signature
export declare const bigintSum: Monoid<bigint>
Added in v1.0.0
booleanAll
boolean monoid under conjunction.
The empty value is true.
Signature
export declare const booleanAll: Monoid<boolean>
Added in v1.0.0
booleanAny
boolean monoid under disjunction.
The empty value is false.
Signature
export declare const booleanAny: Monoid<boolean>
Added in v1.0.0
booleanEqv
boolean monoid under equivalence.
The empty value is true.
Signature
export declare const booleanEqv: Monoid<boolean>
Added in v1.0.0
booleanXor
boolean monoid under exclusive disjunction.
The empty value is false.
Signature
export declare const booleanXor: Monoid<boolean>
Added in v1.0.0
numberMultiply
number monoid under multiplication.
The empty value is 1.
Signature
export declare const numberMultiply: Monoid<number>
Added in v1.0.0
numberSum
number monoid under addition.
The empty value is 0.
Signature
export declare const numberSum: Monoid<number>
Added in v1.0.0
string
Signature
export declare const string: Monoid<string>
Added in v1.0.0
type class
Monoid (interface)
Signature
export interface Monoid<A> extends Semigroup<A> {
readonly empty: A
readonly combineAll: (collection: Iterable<A>) => A
}
Added in v1.0.0