https://github.com/kessler/node-digital-tree
Trie data structure
https://github.com/kessler/node-digital-tree
Last synced: 3 months ago
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Trie data structure
- Host: GitHub
- URL: https://github.com/kessler/node-digital-tree
- Owner: kessler
- License: mit
- Created: 2014-06-07T00:51:48.000Z (over 11 years ago)
- Default Branch: master
- Last Pushed: 2023-02-11T18:01:34.000Z (almost 3 years ago)
- Last Synced: 2025-07-20T07:07:20.822Z (6 months ago)
- Language: JavaScript
- Size: 371 KB
- Stars: 14
- Watchers: 1
- Forks: 0
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# digital tree
A trie data structure implementation.
- thorough testing
- utility: clonable and serializable (to/from json)
- search values by prefix
## Install
npm install --save digital-tree
***version 2.0.0 is almost a complete rewrite and mostly not backwards compatible***
## API
### create() / Ctor
using `create()`` is the recommended way to construct new digital trees:
```javascript
const Trie = require('digital-tree')
const trie = Trie.create()
```
### put(key, value)
Put something in the tree
```javascript
trie.put(['a', 'path', 'to'], 'something')
trie.put(['another', 'thing']) // equivalent to trie.put(['another', 'thing'], true)
trie.put('strings also', 'work') // equivalent to trie.put('strings also'.split(''), 'work')
// ** this only work with the exact key (reference) **
const objectKey = [{ foo: 'bar' }, { bar: 'foo'}]
trie.put(objectKey, { some: 'thing'})
```
### get(key)
Get something from the tree
```javascript
const trie = Trie.create()
trie.put(['a', 'path', 'to'], 'v1')
trie.put('also strings', 'v2')
console.log(trie.get([])) // prints 'foo'
console.log(trie.get(Trie.root)) // prints 'foo'
console.log(trie.get(['a', 'path', 'to'])) // prints 'v1'
console.log(trie.get('also strings')) // prints 'v2'
```
### Iteration
A trie is iterable. Iteration order is either [DFS](https://en.wikipedia.org/wiki/Depth-first_search) or [BFS](https://en.wikipedia.org/wiki/Breadth-first_search)
```javascript
const Trie = require('digital-tree')
const trie = Trie.create()
trie.put('abc', 1)
trie.put('abd', 2)
trie.put('abe', 3)
for (let value of trie) {
}
```
### search(prefix)
Search and return all the values in the tree that are nested under the provided `prefix`.
The results will be an Iterator over the matching values. The order of iteration is defined based on the default ordering of the trie (BFS/DFS)
```javascript
const trie = Trie.create()
trie.put('abc', 1)
trie.put('abd', 2)
trie.put('abe', 3)
console.log(Array.from(trie.search('ab'))) // prints [ 3, 2, 1 ]
console.log(Array.from(trie.search('ab', { includeKeys: true }))) // prints [ [['a','b','e'], 3 ], [['a','b','d'], 2], [['a','b','c'], 1] ]
```
### getSubTrie(key, [shallow=false])
Obtain either a cloned, or shallow copy of a subtree.
```javascript
trie.put('abc', 1)
trie.put('abd', 2)
const subTrie = trie.getSubTrie('ab')
console.log(subTrie.get('c')) // prints 1
console.log(subTrie.get('d')) // prints 2
console.log(subTrie.get('ab')) // prints undefined
```
*setting `shallow` to `true` will create a view rather than cloning the sub trie*
### remove(key)
Remove something from the tree. This will remove the entire subtree that exists under this specified key and return it
as a new trie.
```javascript
trie.put(['a', 'b'], 'ab')
trie.put(['a', 'b', 'c'], 'abc')
trie.put(['a', 'b', 'c', 1], 'abc1')
trie.put(['a', 'b', 'c', 2], 'abc2')
const removed = trie.remove(['a', 'b', 'c'])
console.log(removed.get([1])) // prints 'abc1'
console.log(removed.get([2])) // prints 'abc2'
console.log(trie.get(['a', 'b', 'c', 1])) // prints 'undefined'
console.log(trie.get(['a', 'b'])) // prints 'ab'
```