<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: anyas = import RARA.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: anyas.length; let i: numberi++) {
const const result: R.Result<B, X>result = f: (input: A, i: number) => Result<B, X>f(const as: anyas[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)
}
)