<A, B, X>(f: (input: A, i: number) => Result<B, X>): (
self: Chunk<A>
) => Chunk<B>
<A, B, X>(
self: Chunk<A>,
f: (input: A, i: number) => Result<B, X>
): Chunk<B>Returns a filtered and mapped subset of the elements.
Example (Filtering and mapping values)
import { Chunk, Result } from "effect"
const chunk = Chunk.make("1", "2", "hello", "3", "world")
const numbers = Chunk.filterMap(chunk, (str) => {
const num = parseInt(str)
return isNaN(num) ? Result.failVoid : Result.succeed(num)
})
console.log(Chunk.toArray(numbers)) // [1, 2, 3]
// With index parameter
const evenIndexNumbers = Chunk.filterMap(chunk, (str, i) => {
const num = parseInt(str)
return isNaN(num) || i % 2 !== 0 ? Result.failVoid : Result.succeed(num)
})
console.log(Chunk.toArray(evenIndexNumbers)) // [1]export const const filterMap: {
<A, B, X>(
f: (input: A, i: number) => Result<B, X>
): (self: Chunk<A>) => Chunk<B>
<A, B, X>(
self: Chunk<A>,
f: (input: A, i: number) => Result<B, X>
): Chunk<B>
}
Returns a filtered and mapped subset of the elements.
Example (Filtering and mapping values)
import { Chunk, Result } from "effect"
const chunk = Chunk.make("1", "2", "hello", "3", "world")
const numbers = Chunk.filterMap(chunk, (str) => {
const num = parseInt(str)
return isNaN(num) ? Result.failVoid : Result.succeed(num)
})
console.log(Chunk.toArray(numbers)) // [1, 2, 3]
// With index parameter
const evenIndexNumbers = Chunk.filterMap(chunk, (str, i) => {
const num = parseInt(str)
return isNaN(num) || i % 2 !== 0 ? Result.failVoid : Result.succeed(num)
})
console.log(Chunk.toArray(evenIndexNumbers)) // [1]
filterMap: {
<function (type parameter) A in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>A, function (type parameter) B in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>B, function (type parameter) X in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>X>(f: (input: A, i: number) => Result<B, X>f: (input: Ainput: function (type parameter) A in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>A, i: numberi: number) => type Result<A, E = never> = R.Success<A, E> | R.Failure<A, E>A value that is either Success<A, E> or Failure<A, E>.
When to use
Use when both success and failure should remain available as data and
Option would lose failure information.
Details
- Use
succeed
/
fail
to construct
- Use
match
to fold both branches
- Use
isSuccess
/
isFailure
to narrow the type
E defaults to never, so Result<number> means a result that cannot fail.
Example (Creating and matching a Result)
import { Result } from "effect"
const success = Result.succeed(42)
const failure = Result.fail("something went wrong")
const message = Result.match(success, {
onSuccess: (value) => `Success: ${value}`,
onFailure: (error) => `Error: ${error}`
})
console.log(message)
// Output: "Success: 42"
Namespace containing type-level utilities for extracting the inner types
of a Result.
Example (Extracting inner types)
import type { Result } from "effect"
type R = Result.Result<number, string>
// number
type A = Result.Result.Success<R>
// string
type E = Result.Result.Failure<R>
Result<function (type parameter) B in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>B, function (type parameter) X in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>X>): (self: Chunk<A>(parameter) self: {
length: number;
right: Chunk<A>;
left: Chunk<A>;
backing: Backing<A>;
depth: number;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
interface Chunk<out A>A Chunk is an immutable, ordered collection optimized for efficient concatenation and access patterns.
Example (Inspecting chunk values)
import { Chunk } from "effect"
const chunk: Chunk.Chunk<number> = Chunk.make(1, 2, 3)
console.log(chunk.length) // 3
console.log(Chunk.toArray(chunk)) // [1, 2, 3]
A namespace containing utility types for Chunk operations.
Example (Working with Chunk utility types)
import type { Chunk } from "effect"
// Extract the element type from a Chunk
declare const chunk: Chunk.Chunk<string>
type ElementType = Chunk.Chunk.Infer<typeof chunk> // string
// Create a preserving non-emptiness
declare const nonEmptyChunk: Chunk.NonEmptyChunk<number>
type WithString = Chunk.Chunk.With<typeof nonEmptyChunk, string> // Chunk.NonEmptyChunk<string>
Chunk<function (type parameter) A in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>A>) => interface Chunk<out A>A Chunk is an immutable, ordered collection optimized for efficient concatenation and access patterns.
Example (Inspecting chunk values)
import { Chunk } from "effect"
const chunk: Chunk.Chunk<number> = Chunk.make(1, 2, 3)
console.log(chunk.length) // 3
console.log(Chunk.toArray(chunk)) // [1, 2, 3]
A namespace containing utility types for Chunk operations.
Example (Working with Chunk utility types)
import type { Chunk } from "effect"
// Extract the element type from a Chunk
declare const chunk: Chunk.Chunk<string>
type ElementType = Chunk.Chunk.Infer<typeof chunk> // string
// Create a preserving non-emptiness
declare const nonEmptyChunk: Chunk.NonEmptyChunk<number>
type WithString = Chunk.Chunk.With<typeof nonEmptyChunk, string> // Chunk.NonEmptyChunk<string>
Chunk<function (type parameter) B in <A, B, X>(f: (input: A, i: number) => Result<B, X>): (self: Chunk<A>) => Chunk<B>B>
<function (type parameter) A in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>A, function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B, function (type parameter) X in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>X>(self: Chunk<A>(parameter) self: {
length: number;
right: Chunk<A>;
left: Chunk<A>;
backing: Backing<A>;
depth: number;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
interface Chunk<out A>A Chunk is an immutable, ordered collection optimized for efficient concatenation and access patterns.
Example (Inspecting chunk values)
import { Chunk } from "effect"
const chunk: Chunk.Chunk<number> = Chunk.make(1, 2, 3)
console.log(chunk.length) // 3
console.log(Chunk.toArray(chunk)) // [1, 2, 3]
A namespace containing utility types for Chunk operations.
Example (Working with Chunk utility types)
import type { Chunk } from "effect"
// Extract the element type from a Chunk
declare const chunk: Chunk.Chunk<string>
type ElementType = Chunk.Chunk.Infer<typeof chunk> // string
// Create a preserving non-emptiness
declare const nonEmptyChunk: Chunk.NonEmptyChunk<number>
type WithString = Chunk.Chunk.With<typeof nonEmptyChunk, string> // Chunk.NonEmptyChunk<string>
Chunk<function (type parameter) A in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>A>, f: (input: A, i: number) => Result<B, X>f: (input: Ainput: function (type parameter) A in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>A, i: numberi: number) => type Result<A, E = never> = R.Success<A, E> | R.Failure<A, E>A value that is either Success<A, E> or Failure<A, E>.
When to use
Use when both success and failure should remain available as data and
Option would lose failure information.
Details
- Use
succeed
/
fail
to construct
- Use
match
to fold both branches
- Use
isSuccess
/
isFailure
to narrow the type
E defaults to never, so Result<number> means a result that cannot fail.
Example (Creating and matching a Result)
import { Result } from "effect"
const success = Result.succeed(42)
const failure = Result.fail("something went wrong")
const message = Result.match(success, {
onSuccess: (value) => `Success: ${value}`,
onFailure: (error) => `Error: ${error}`
})
console.log(message)
// Output: "Success: 42"
Namespace containing type-level utilities for extracting the inner types
of a Result.
Example (Extracting inner types)
import type { Result } from "effect"
type R = Result.Result<number, string>
// number
type A = Result.Result.Success<R>
// string
type E = Result.Result.Failure<R>
Result<function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B, function (type parameter) X in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>X>): interface Chunk<out A>A Chunk is an immutable, ordered collection optimized for efficient concatenation and access patterns.
Example (Inspecting chunk values)
import { Chunk } from "effect"
const chunk: Chunk.Chunk<number> = Chunk.make(1, 2, 3)
console.log(chunk.length) // 3
console.log(Chunk.toArray(chunk)) // [1, 2, 3]
A namespace containing utility types for Chunk operations.
Example (Working with Chunk utility types)
import type { Chunk } from "effect"
// Extract the element type from a Chunk
declare const chunk: Chunk.Chunk<string>
type ElementType = Chunk.Chunk.Infer<typeof chunk> // string
// Create a preserving non-emptiness
declare const nonEmptyChunk: Chunk.NonEmptyChunk<number>
type WithString = Chunk.Chunk.With<typeof nonEmptyChunk, string> // Chunk.NonEmptyChunk<string>
Chunk<function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B>
} = dual<(...args: Array<any>) => any, <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>) => Chunk<B>>(arity: 2, body: <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>) => Chunk<B>): ((...args: Array<any>) => any) & (<A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>) => Chunk<B>) (+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) A in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>A, function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B, function (type parameter) X in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>X>(self: Chunk<A>(parameter) self: {
length: number;
right: Chunk<A>;
left: Chunk<A>;
backing: Backing<A>;
depth: number;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
interface Chunk<out A>A Chunk is an immutable, ordered collection optimized for efficient concatenation and access patterns.
Example (Inspecting chunk values)
import { Chunk } from "effect"
const chunk: Chunk.Chunk<number> = Chunk.make(1, 2, 3)
console.log(chunk.length) // 3
console.log(Chunk.toArray(chunk)) // [1, 2, 3]
A namespace containing utility types for Chunk operations.
Example (Working with Chunk utility types)
import type { Chunk } from "effect"
// Extract the element type from a Chunk
declare const chunk: Chunk.Chunk<string>
type ElementType = Chunk.Chunk.Infer<typeof chunk> // string
// Create a preserving non-emptiness
declare const nonEmptyChunk: Chunk.NonEmptyChunk<number>
type WithString = Chunk.Chunk.With<typeof nonEmptyChunk, string> // Chunk.NonEmptyChunk<string>
Chunk<function (type parameter) A in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>A>, f: (input: A, i: number) => Result<B, X>f: (input: Ainput: function (type parameter) A in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>A, i: numberi: number) => type Result<A, E = never> = R.Success<A, E> | R.Failure<A, E>A value that is either Success<A, E> or Failure<A, E>.
When to use
Use when both success and failure should remain available as data and
Option would lose failure information.
Details
- Use
succeed
/
fail
to construct
- Use
match
to fold both branches
- Use
isSuccess
/
isFailure
to narrow the type
E defaults to never, so Result<number> means a result that cannot fail.
Example (Creating and matching a Result)
import { Result } from "effect"
const success = Result.succeed(42)
const failure = Result.fail("something went wrong")
const message = Result.match(success, {
onSuccess: (value) => `Success: ${value}`,
onFailure: (error) => `Error: ${error}`
})
console.log(message)
// Output: "Success: 42"
Namespace containing type-level utilities for extracting the inner types
of a Result.
Example (Extracting inner types)
import type { Result } from "effect"
type R = Result.Result<number, string>
// number
type A = Result.Result.Success<R>
// string
type E = Result.Result.Failure<R>
Result<function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B, function (type parameter) X in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>X>): interface Chunk<out A>A Chunk is an immutable, ordered collection optimized for efficient concatenation and access patterns.
Example (Inspecting chunk values)
import { Chunk } from "effect"
const chunk: Chunk.Chunk<number> = Chunk.make(1, 2, 3)
console.log(chunk.length) // 3
console.log(Chunk.toArray(chunk)) // [1, 2, 3]
A namespace containing utility types for Chunk operations.
Example (Working with Chunk utility types)
import type { Chunk } from "effect"
// Extract the element type from a Chunk
declare const chunk: Chunk.Chunk<string>
type ElementType = Chunk.Chunk.Infer<typeof chunk> // string
// Create a preserving non-emptiness
declare const nonEmptyChunk: Chunk.NonEmptyChunk<number>
type WithString = Chunk.Chunk.With<typeof nonEmptyChunk, string> // Chunk.NonEmptyChunk<string>
Chunk<function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B> => {
const const as: A[]as = import RARA.const fromIterable: <A>(
collection: Iterable<A>
) => A[]
Converts an Iterable to an Array.
When to use
Use to convert any Iterable (Set, Generator, etc.) into an array.
Details
If the input is already an array, this returns it by reference without
copying. Otherwise, it creates a new array from the iterable. Use copy if
you need a fresh array even when the input is already an array.
Example (Converting a Set to an array)
import { Array } from "effect"
const result = Array.fromIterable(new Set([1, 2, 3]))
console.log(result) // [1, 2, 3]
fromIterable(self: Chunk<A>(parameter) self: {
length: number;
right: Chunk<A>;
left: Chunk<A>;
backing: Backing<A>;
depth: number;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
const out: B[]out: interface Array<T>Array<function (type parameter) B in <A, B, X>(self: Chunk<A>, f: (input: A, i: number) => Result<B, X>): Chunk<B>B> = []
for (let let i: numberi = 0; let i: numberi < const as: A[]as.Array<T>.length: numberGets or sets the length of the array. This is a number one higher than the highest index in the array.
length; let i: numberi++) {
const const result: R.Result<B, X>result = f: (input: A, i: number) => Result<B, X>f(const as: A[]as[let i: numberi], let i: numberi)
if (import RR.const isSuccess: <A, E>(
self: Result<A, E>
) => self is Success<A, E>
Checks whether a Result is a Success.
When to use
Use to narrow a known Result to the Success variant.
Details
- Acts as a TypeScript type guard, narrowing to
Success<A, E>
- After narrowing, you can access
.success to read the value
Example (Narrowing to success)
import { Result } from "effect"
const result = Result.succeed(42)
if (Result.isSuccess(result)) {
console.log(result.success)
// Output: 42
}
isSuccess(const result: R.Result<B, X>result)) {
const out: B[]out.Array<B>.push(...items: B[]): numberAppends new elements to the end of an array, and returns the new length of the array.
push(const result: R.Success<B, X>const result: {
_tag: "Success";
_op: "Success";
success: A;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
Success<B, X>.success: Bsuccess)
}
}
return const fromArrayUnsafe: <A>(
self: ReadonlyArray<A>
) => Chunk<A>
Wraps an array into a chunk without copying.
When to use
Use when the input array can be shared with the resulting Chunk and avoiding
a copy matters.
Gotchas
Mutating the source array after wrapping can mutate the resulting Chunk.
Example (Creating chunks without copying arrays)
import { Chunk } from "effect"
const array = [1, 2, 3, 4, 5]
const chunk = Chunk.fromArrayUnsafe(array)
console.log(Chunk.toArray(chunk)) // [1, 2, 3, 4, 5]
// Warning: Since this doesn't copy the array, mutations affect the chunk
array[0] = 999
console.log(Chunk.toArray(chunk)) // [999, 2, 3, 4, 5]
fromArrayUnsafe(const out: B[]out)
}
)