<K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (
self: ReadonlyRecord<K, A>
) => Record<K2, A>
<K extends string, A, K2 extends string>(
self: ReadonlyRecord<K, A>,
f: (key: K, a: A) => K2
): Record<K2, A>Maps the keys of a ReadonlyRecord while preserving the corresponding values.
Example (Mapping record keys)
import { Record } from "effect"
import * as assert from "node:assert"
assert.deepStrictEqual(
Record.mapKeys({ a: 3, b: 5 }, (key) => key.toUpperCase()),
{ A: 3, B: 5 }
)mapping
Source effect/Record.ts:65122 lines
export const const mapKeys: {
<K extends string, A, K2 extends string>(
f: (key: K, a: A) => K2
): (self: ReadonlyRecord<K, A>) => Record<K2, A>
<K extends string, A, K2 extends string>(
self: ReadonlyRecord<K, A>,
f: (key: K, a: A) => K2
): Record<K2, A>
}
Maps the keys of a ReadonlyRecord while preserving the corresponding values.
Example (Mapping record keys)
import { Record } from "effect"
import * as assert from "node:assert"
assert.deepStrictEqual(
Record.mapKeys({ a: 3, b: 5 }, (key) => key.toUpperCase()),
{ A: 3, B: 5 }
)
mapKeys: {
<function (type parameter) K in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>K extends string, function (type parameter) A in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>A, function (type parameter) K2 in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>K2 extends string>(
f: (key: K, a: A) => K2f: (key: K extends stringkey: function (type parameter) K in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>K, a: Aa: function (type parameter) A in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>A) => function (type parameter) K2 in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>K2
): (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, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>K, function (type parameter) A in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>A>) => type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<function (type parameter) K2 in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>K2, function (type parameter) A in <K extends string, A, K2 extends string>(f: (key: K, a: A) => K2): (self: ReadonlyRecord<K, A>) => Record<K2, A>A>
<function (type parameter) K in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K extends string, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A, function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2 extends string>(
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, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A>,
f: (key: K, a: A) => K2f: (key: K extends stringkey: function (type parameter) K in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K, a: Aa: function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A) => function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2
): type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A>
} = import dualdual(
2,
<function (type parameter) K in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K extends string, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A, function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2 extends string>(
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, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A>,
f: (key: K, a: A) => K2f: (key: K extends stringkey: function (type parameter) K in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K, a: Aa: function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A) => function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2
): type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A> => {
const const out: Record<K2, A>out: type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<function (type parameter) K2 in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>K2, function (type parameter) A in <K extends string, A, K2 extends string>(self: ReadonlyRecord<K, A>, f: (key: K, a: A) => K2): Record<K2, A>A> = {} as any
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)) {
const const a: ReadonlyRecord<K, A>[K]a = self: ReadonlyRecord<K, A>self[const key: K extends stringkey]
const out: Record<K2, A>out[f: (key: K, a: A) => K2f(const key: K extends stringkey, const a: ReadonlyRecord<K, A>[K]a)] = const a: ReadonlyRecord<K, A>[K]a
}
return const out: Record<K2, A>out
}
)