<A, K extends string>(predicate: (value: A, key: K) => boolean): (
self: ReadonlyRecord<K, A>
) => boolean
<K extends string, A>(
self: ReadonlyRecord<K, A>,
predicate: (value: A, key: K) => boolean
): booleanChecks whether any entry in a record meets a specific condition.
Example (Checking for any matching value)
import { Record } from "effect"
import * as assert from "node:assert"
assert.deepStrictEqual(Record.some({ a: 1, b: 2 }, (n) => n > 1), true)
assert.deepStrictEqual(Record.some({ a: 1, b: 2 }, (n) => n > 2), false)export const const some: {
<A, K extends string>(
predicate: (value: A, key: K) => boolean
): (self: ReadonlyRecord<K, A>) => boolean
<K extends string, A>(
self: ReadonlyRecord<K, A>,
predicate: (value: A, key: K) => boolean
): boolean
}
Checks whether any entry in a record meets a specific condition.
Example (Checking for any matching value)
import { Record } from "effect"
import * as assert from "node:assert"
assert.deepStrictEqual(Record.some({ a: 1, b: 2 }, (n) => n > 1), true)
assert.deepStrictEqual(Record.some({ a: 1, b: 2 }, (n) => n > 2), false)
some: {
<function (type parameter) A in <A, K extends string>(predicate: (value: A, key: K) => boolean): (self: ReadonlyRecord<K, A>) => booleanA, function (type parameter) K in <A, K extends string>(predicate: (value: A, key: K) => boolean): (self: ReadonlyRecord<K, A>) => booleanK extends string>(predicate: (value: A, key: K) => booleanpredicate: (value: Avalue: function (type parameter) A in <A, K extends string>(predicate: (value: A, key: K) => boolean): (self: ReadonlyRecord<K, A>) => booleanA, key: K extends stringkey: function (type parameter) K in <A, K extends string>(predicate: (value: A, key: K) => boolean): (self: ReadonlyRecord<K, A>) => booleanK) => boolean): (self: ReadonlyRecord<K, A>self: type ReadonlyRecord<in out K extends string | symbol, out A> = { readonly [P in K]: A; }Represents a readonly record with keys of type K and values of type A.
This is the foundational type for immutable key-value mappings in Effect.
Example (Defining a readonly record type)
import type { Record } from "effect"
// Creating a readonly record type
type UserRecord = Record.ReadonlyRecord<"name" | "age", string | number>
const user: UserRecord = {
name: "John",
age: 30
}
Namespace containing utility types for working with readonly records.
These types help with type-level operations on record keys and values.
Example (Using readonly record helper types)
import type { Record } from "effect"
// Using NonLiteralKey to convert literal keys to generic types
type GenericKey = Record.ReadonlyRecord.NonLiteralKey<"foo" | "bar"> // string
// Using IntersectKeys to find common keys between record types
type CommonKeys = Record.ReadonlyRecord.IntersectKeys<"a" | "b", "b" | "c"> // "b"
ReadonlyRecord<function (type parameter) K in <A, K extends string>(predicate: (value: A, key: K) => boolean): (self: ReadonlyRecord<K, A>) => booleanK, function (type parameter) A in <A, K extends string>(predicate: (value: A, key: K) => boolean): (self: ReadonlyRecord<K, A>) => booleanA>) => boolean
<function (type parameter) K in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanK extends string, function (type parameter) A in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanA>(self: ReadonlyRecord<K, A>self: type ReadonlyRecord<in out K extends string | symbol, out A> = { readonly [P in K]: A; }Represents a readonly record with keys of type K and values of type A.
This is the foundational type for immutable key-value mappings in Effect.
Example (Defining a readonly record type)
import type { Record } from "effect"
// Creating a readonly record type
type UserRecord = Record.ReadonlyRecord<"name" | "age", string | number>
const user: UserRecord = {
name: "John",
age: 30
}
Namespace containing utility types for working with readonly records.
These types help with type-level operations on record keys and values.
Example (Using readonly record helper types)
import type { Record } from "effect"
// Using NonLiteralKey to convert literal keys to generic types
type GenericKey = Record.ReadonlyRecord.NonLiteralKey<"foo" | "bar"> // string
// Using IntersectKeys to find common keys between record types
type CommonKeys = Record.ReadonlyRecord.IntersectKeys<"a" | "b", "b" | "c"> // "b"
ReadonlyRecord<function (type parameter) K in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanK, function (type parameter) A in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanA>, predicate: (value: A, key: K) => booleanpredicate: (value: Avalue: function (type parameter) A in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanA, key: K extends stringkey: function (type parameter) K in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanK) => boolean): boolean
} = dual<(...args: Array<any>) => any, <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean) => boolean>(arity: 2, body: <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean) => boolean): ((...args: Array<any>) => any) & (<K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean) => 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,
<function (type parameter) K in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanK extends string, function (type parameter) A in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanA>(self: ReadonlyRecord<K, A>self: type ReadonlyRecord<in out K extends string | symbol, out A> = { readonly [P in K]: A; }Represents a readonly record with keys of type K and values of type A.
This is the foundational type for immutable key-value mappings in Effect.
Example (Defining a readonly record type)
import type { Record } from "effect"
// Creating a readonly record type
type UserRecord = Record.ReadonlyRecord<"name" | "age", string | number>
const user: UserRecord = {
name: "John",
age: 30
}
Namespace containing utility types for working with readonly records.
These types help with type-level operations on record keys and values.
Example (Using readonly record helper types)
import type { Record } from "effect"
// Using NonLiteralKey to convert literal keys to generic types
type GenericKey = Record.ReadonlyRecord.NonLiteralKey<"foo" | "bar"> // string
// Using IntersectKeys to find common keys between record types
type CommonKeys = Record.ReadonlyRecord.IntersectKeys<"a" | "b", "b" | "c"> // "b"
ReadonlyRecord<function (type parameter) K in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanK, function (type parameter) A in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanA>, predicate: (value: A, key: K) => booleanpredicate: (value: Avalue: function (type parameter) A in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanA, key: K extends stringkey: function (type parameter) K in <K extends string, A>(self: ReadonlyRecord<K, A>, predicate: (value: A, key: K) => boolean): booleanK) => boolean): boolean => {
for (const const key: K extends stringkey of const keys: <
K extends string | symbol,
A
>(
self: ReadonlyRecord<K, A>
) => Array<K & string>
Retrieves the keys of a given record as an array.
Example (Getting record keys)
import { Record } from "effect"
import * as assert from "node:assert"
assert.deepStrictEqual(Record.keys({ a: 1, b: 2, c: 3 }), ["a", "b", "c"])
keys(self: ReadonlyRecord<K, A>self)) {
if (predicate: (value: A, key: K) => booleanpredicate(self: ReadonlyRecord<K, A>self[const key: K extends stringkey], const key: K extends stringkey)) {
return true
}
}
return false
}
)