List.Builder | /core/mod.ts | rimbu@1.2.0

interface List.Builder

import { type List } from "https://deno.land/x/rimbu@1.2.0/core/mod.ts";
const { Builder } = List;

A mutable builder to create immutable List instances in a more efficient way. See the List documentation and the List.Builder API documentation

Examples

Example 1

const b = List.builder<T>();
b.append(1);
b.prepend(2);
b.insert(1, 3);
b.build().toArray();
// => [2, 3, 1]

Type Parameters

Properties

readonly

length: number

Returns the amount of values in the builder.

readonly

isEmpty: boolean

Returns true if there are no values in the builder.

Methods

get(index: number): T | undefined

Returns the value in the List builder at the given index.

get<O>(index: number, otherwise: OptLazy<O>): T | O

updateAt(index: number, update: Update<T>): T | undefined

Updates the element at the given index with the given update value or function.

updateAt<O>(

index: number,

update: Update<T>,

otherwise: OptLazy<O>,

): T | O

set(index: number, value: T): T | undefined

Sets the element at the given index to the given value.

set<O>(

index: number,

value: T,

otherwise: OptLazy<O>,

): T | O

prepend(value: T): void

Adds the given value to the start of the builder values.

append(value: T): void

Adds the given value to the end of the builder values.

appendAll(values: StreamSource<T>): void

Adds all given values at the end of the builder values

insert(index: number, value: T): void

Inserts the given value at the given index in the builder.

remove(index: number): T | undefined

Removes the value at the given index in the builder.

remove<O>(index: number, otherwise: OptLazy<O>): T | O

forEach(f: (

value: T,

index: number,

halt: () => void,

) => void, options?: { reversed?: boolean; state?: TraverseState; }): void

Performs given function f for each value of the List builder.

build(): List<T>

Returns an immutable instance containing the values in this builder.

buildMap<T2 = T>(mapFun: (value: T) => T2): List<T2>

Returns an immutable instance containing the result of applying given mapFun to each value in the builder.