Use DataMap when you want native Map semantics with collection helpers. Use ReadonlyMap when a consumer should not mutate the store. Use map() when you want a callable ge

Map

Extended Map utilities plus callable and readonly wrappers.

Import

import { DataMap, ReadonlyMap, map } from '@stackpress/lib';

When To Use It

Use DataMap when you want native Map semantics with collection helpers. Use ReadonlyMap when a consumer should not mutate the store. Use map() when you want a callable getter plus Map methods on one value.

API

Constructor

const users = new DataMap<string, number>([
  ['ada', 1],
  ['grace', 2]
]);

ReadonlyMap takes the same entry-array shape.

DataMap Methods

Method	Returns	Notes
`filter(callback)`	new `DataMap` subclass	Filters entries by value and key.
`find(callback)`	`[K, V] \	undefined`	First matching entry.
`findKey(callback)`	`K \	undefined`	First matching key.
`findValue(callback)`	`V \	undefined`	First matching value.
`first()`	`V \	undefined`	Alias for `index(0)` .
`index(index)`	`V \	undefined`	Value by insertion order.
`last()`	`V \	undefined`	Value at `size - 1` .
`map(callback)`	new `DataMap<K, T>`	Maps values while preserving keys.
`toArray()`	`V[]`	Values only.
`toObject()`	`Record<string, V>`	Converts entries to a plain object.
`toString(replacer?, space?)`	`string`	JSON string of `toObject()` .

ReadonlyMap Methods

ReadonlyMap exposes read and transform helpers over an internal DataMap :

entries()
filter(callback)
find(callback)
findKey(callback)
findValue(callback)
forEach(iterator)
get(key)
has(key)
keys()
map(callback)
size
toObject()
toString(replacer?, space?)
values()

Callable Helper

const headers = map<string, string>();

headers.set('content-type', 'application/json');
headers('content-type');
headers.get('content-type');

map(data?) returns a callable CallableMap<K, V> . It supports normal DataMap methods and a getter function signature.

Example

import { DataMap } from '@stackpress/lib';

const scores = new DataMap<string, number>();
scores.set('one', 1);
scores.set('two', 2);
scores.set('three', 3);

const passing = scores.filter(value => value >= 2);
const first = scores.first();
const serialized = scores.toString();

Map

Map