import { type BiMap } from "https://deno.land/x/froebel@v0.20.0/bimap.ts";
Bidirectional map. Maps two sets of keys in a one-to-one relation.
Both sides are accessible (at .left & .right, or at their respective alias if one was provided in the constructor) with an interface similar to that of the built-in Map and the same iteration behavior.
Examples
Example 1
Example 1
const nums = BiMap.from({ one: 1, two: 2 })
// different ways of iterating over the entries
[...nums.left] // [['one',1], ['two',2]]
[...nums.right] // [[1,'one'], [2,'two']]
[...nums.left.keys()] // ['one', 'two']
[...nums.left.values()] // [1, 2]
[...nums.right.keys()] // [1, 2]
[...nums.right.values()] // ['one', 'two']
[...nums] // [['one',1], ['two',2]]
[...nums.right.entries()] // [[1,'one'], [2,'two']]
Object.fromEntries(nums.right) // { '1': 'one', '2': 'two' }
// setting a value
nums.left.three = 3
// when accessing a property using bracket notation (i.e. nums.right[4]),
// JavaScript coerces the key to a string, so keys that aren't strings or
// symbols must be accessed using the same access methods known from Map.
nums.right.set(4, 'four')
// remapping values
nums.left.tres = 3 // {one: 1, two: 2, tres: 3, four: 4}
nums.right.set(4, 'cuatro') // {one: 1, two: 2, tres: 3, cuatro: 4}
// deleting
delete nums.left.tres // {one: 1, two: 2, cuatro: 4}
nums.right.delete(4) // {one: 1, two: 2}
// reversing the map
const num2Name = nums.reverse()
console.log([...num2Name.left]) // [[1,'one'], [2,'two']]
console.log(Object.fromEntries(num2Name.right)) // {one: 1, two: 2}
// other methods known from built-in Map
nums.size // 2
nums.[left|right].size // 2
nums.clear() // equivalent to nums.[left|right].clear()
console.log(nums.size) // 0
Example 2
Example 2
// giving aliases to both sides
const dictionary = new BiMap(
[
['hello', 'hallo'],
['bye', 'tschüss'],
],
'en',
'de'
)
dictionary.de.get('hallo') // 'hello'
dictionary.en.get('bye') // 'tschüss'
delete dictionary.de.hallo
console.log(Object.fromEntries(dictionary.en)) // { bye: 'tschüss' }
// you can also use the BiMap.alias method:
BiMap.alias('en', 'de')<string, string>()
BiMap.alias('en', 'de')([['hello', 'hallo']])
BiMap.alias('en', 'de')(new Map<string, string>())
BiMap.alias('en', 'de')({ hello: 'hallo' })
BiMap.alias('en', 'de')(new Set(['hello']), new Set(['hallo']))
// the same arguments can be used with BiMap.from, e.g.:
BiMap.from(new Set<number>(), new Set<number>())