<A>(self: Chunk<Option<A>>): Chunk<A>Filters out optional values
Example (Compacting optional values)
import { Chunk, Option } from "effect"
const chunk = Chunk.make(Option.some(1), Option.none(), Option.some(3))
const result = Chunk.compact(chunk)
console.log(Chunk.toArray(result)) // [1, 3]export const const compact: <A>(
self: Chunk<Option<A>>
) => Chunk<A>
Filters out optional values
Example (Compacting optional values)
import { Chunk, Option } from "effect"
const chunk = Chunk.make(Option.some(1), Option.none(), Option.some(3))
const result = Chunk.compact(chunk)
console.log(Chunk.toArray(result)) // [1, 3]
compact = <function (type parameter) A in <A>(self: Chunk<Option<A>>): Chunk<A>A>(self: Chunk<Option<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<type Option<A> = O.None<A> | O.Some<A>The Option data type represents optional values. An Option<A> is either
Some<A>, containing a value of type A, or None, representing absence.
When to use
Use to represent initial values that may not yet exist
- Returning from partial functions (not defined for all inputs)
- Managing optional fields in data structures
Namespace containing utility types for Option.
When to use
Use to access type-level helpers associated with Option.
Option<function (type parameter) A in <A>(self: Chunk<Option<A>>): Chunk<A>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) A in <A>(self: Chunk<Option<A>>): Chunk<A>A> => {
const const out: A[]out: interface Array<T>Array<function (type parameter) A in <A>(self: Chunk<Option<A>>): Chunk<A>A> = []
for (const const option: Option<A>option of self: Chunk<Option<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;
}
import OO.const isSome: <A>(
self: Option<A>
) => self is Some<A>
Checks whether an Option contains a value (Some).
When to use
Use when you need to branch on a present Option before accessing .value.
Details
- Acts as a type guard, narrowing to
Some<A>
Example (Checking for Some)
import { Option } from "effect"
console.log(Option.isSome(Option.some(1)))
// Output: true
console.log(Option.isSome(Option.none()))
// Output: false
isSome(const option: Option<A>option)) {
const out: A[]out.Array<A>.push(...items: A[]): numberAppends new elements to the end of an array, and returns the new length of the array.
push(const option: O.Some<A>const option: {
_tag: "Some";
_op: "Some";
value: A;
valueOrUndefined: 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;
}
Some<A>.value: Avalue)
}
}
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: A[]out)
}