<A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean
(self: Iterable<A>, a: A): boolean
}Returns a membership-test function using a custom equivalence.
When to use
Use when checking membership with caller-provided equality instead of
Equal.equivalence().
Example (Checking with custom equality)
import { Array, pipe } from "effect"
const containsNumber = Array.containsWith((a: number, b: number) => a === b)
console.log(pipe([1, 2, 3, 4], containsNumber(3))) // trueexport const const containsWith: <A>(
isEquivalent: (self: A, that: A) => boolean
) => {
(a: A): (self: Iterable<A>) => boolean
(self: Iterable<A>, a: A): boolean
}
Returns a membership-test function using a custom equivalence.
When to use
Use when checking membership with caller-provided equality instead of
Equal.equivalence().
Example (Checking with custom equality)
import { Array, pipe } from "effect"
const containsNumber = Array.containsWith((a: number, b: number) => a === b)
console.log(pipe([1, 2, 3, 4], containsNumber(3))) // true
containsWith = <function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
isEquivalent: (self: A, that: A) => booleanisEquivalent: (self: Aself: function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
that: Athat: function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
a: Aa: function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
self: Iterable<A>self: interface Iterable<T, TReturn = any, TNext = any>Iterable<function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
self: Iterable<A>self: interface Iterable<T, TReturn = any, TNext = any>Iterable<function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
a: Aa: function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
dual<(...args: Array<any>) => any, (self: Iterable<A>, a: A) => boolean>(arity: 2, body: (self: Iterable<A>, a: A) => boolean): ((...args: Array<any>) => any) & ((self: Iterable<A>, a: A) => boolean) (+1 overload)Creates a function that can be called in data-first style or data-last
(pipe-friendly) style.
When to use
Use to expose one implementation through both direct and pipe-friendly
call styles.
Details
Pass either the arity of the uncurried function or a predicate that decides
whether the current call is data-first. Arity is the common case. Use a
predicate when optional arguments make arity ambiguous.
Example (Selecting data-first or data-last style by arity)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(2, (self, that) => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Defining overloads with call signatures)
import { Function, pipe } from "effect"
const sum: {
(that: number): (self: number) => number
(self: number, that: number): number
} = Function.dual(2, (self: number, that: number): number => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Selecting data-first or data-last style with a predicate)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(
(args) => args.length === 2,
(self, that) => self + that
)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
dual(2, (self: Iterable<A>self: interface Iterable<T, TReturn = any, TNext = any>Iterable<function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
a: Aa: function (type parameter) A in <A>(isEquivalent: (self: A, that: A) => boolean): {
(a: A): (self: Iterable<A>) => boolean;
(self: Iterable<A>, a: A): boolean;
}
const i: Ai of self: Iterable<A>self) {
if (isEquivalent: (self: A, that: A) => booleanisEquivalent(a: Aa, const i: Ai)) {
return true
}
}
return false
})