composite-map
v1.1.0
Published
A module for mapping between multi-part keys and values.
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composite-map
A module for mapping between multi-part keys and values
Install
npm install composite-map
Usage
const { CompositeMap } = require("composite-map");
const map = new CompositeMap();
map.set(["one", 2, true], "test-value");
map.get(["one", 2, true]);
//=> 'test-value'
API
new CompositeMap([entries, [options]])
entries
Type: CompositeMap
Array
Elements to populate the map with. Array
inputs must be in the same form as those created by the
CompositeMap.prototype.toJSON() method.
const map1 = new CompositeMap();
const map2 = new CompositeMap(map1);
const map3 = new CompositeMap([["one", "test-value"], ["two", "test-value-2"]], { keyLength: 1 });
const map4 = new CompositeMap([["one", [[2, "test-value"]]]], { keyLength: 2 });
const map5 = new CompositeMap([["one", [[2, [[true, "test-value"]]]]]], { keyLength: 3 });
options
Type: Object
copy
Type: "on-write"
"keys"
Default: "keys"
Determines when the keys for the provided CompositeMap
are copied.
"on-write"
Copy keys as changes are made.
"keys"
Copy all keys immediately.
keyLength
Type: number
Manually specify the length of keys. Only used when constructing using an array of elements.
CompositeMap.prototype.clear()
Removes all key/value pairs from the CompositeMap
object.
CompositeMap.prototype.delete(key)
Returns true
if an element in the CompositeMap
object existed and has been removed, or false
if the element does
not exist.
key
Type: Array
The key of the element to be deleted. Shorter keys will delete all elements with matching keys.
CompositeMap.prototype.entries()
Returns a new Iterator
object that contains an array of [key, value]
for each element in the CompositeMap
object.
CompositeMap.prototype.forEach(callbackFn)
Calls callbackFn once for each key-value pair present in the CompositeMap
object.
CompositeMap.prototype.get(key)
Returns the value associated to the key
, or undefined
if there is none.
key
Type: Array
The key
of the element to be returned. Shorter keys will return the Map
object associated to the key if one exists.
CompositeMap.prototype.has(key)
Returns a boolean asserting whether a value has been associated to the key
in the CompositeMap
object or not.
key
Type: Array
The key
of the element to be found. Shorter keys will find any elements with matching keys.
CompositeMap.prototype.keys()
Returns a new Iterator
object that contains the keys for each element in the CompositeMap
object.
CompositeMap.prototype.set(key, value)
Sets the value of the key
in the CompositeMap
object. Returns the CompositeMap
object.
key
Type: Array
The key
to set the value for. All keys must have the same Array
length.
value
Type: any
The value to store.
CompositeMap.prototype.toJSON()
Returns a tree-like Array
structure containing all elements in the CompositeMap
object.
const map = new CompositeMap();
map.set(["one", 2, true], "test-value");
const json = JSON.stringify(map);
console.log(json);
//=>[["one", [[2, [[true, "test-value"]]]]]]
const map2 = new CompositeMap(JSON.parse(json), { keyLength: 3 });
CompositeMap.prototype.values()
Returns a new Iterator
object that contains the values for each element in the CompositeMap
object.
CompositeMap.prototype[@@iterator]()
Returns a new Iterator
object that contains an array of [key, value]
for each element in the CompositeMap
object.
TypeScript
To provide better typing support, you can import copies of the CompositeMap
class typed for the length of key
being
used.
import { CompositeMap3 } from "composite-map";
const map = new CompositeMap3<string, number, boolean, string>();
map.set(["one", 2, true], "test-value");
const value: string = map.get(["one", 2, true]);
const subMap: Map<boolean, string> = map.get(["one", 2]);
Related
- composite-object - A module for mapping between multi-part string keys and values.
- json-key-map - A module for mapping between JSON keys and values.
License
Sources
Some text from this readme was sourced from developer.mozilla.org.