exact-trie

Node.js implementation of a trie and a radix tree tailored towards exact matches.

Methods

new ExactTrie([options])

Used to create the trie: const trie = new ExactTrie();.

• options (optional)
  • ignoreCase (true, optional) set to true to convert all keys to lower case.

trie.put(key, value, [reverse])

Used to insert elements into the trie.

• key search key, must be a string.
• value value to be inserted, can by any type.
• reverse (false, optional) set to true to reverse the key before inserting.

trie.get(key, [reverse])

Used to retrieve elements from the trie. Returns undefined if the key is not present in the trie.

• key search key, must be a string.
• reverse (false, optional) set to true to reverse the key before searching.

trie.has(key, [reverse])

Used to check if the key is present in the true. Returns a boolean.

• key search key, must be a string.
• reverse (false, optional) set to true to reverse the key before searching.

trie.getWithCheckpoints(string, [checkpointChar], [reverse])

Used to retrieve the value corresponding to they key that matches the longest prefix of string. If there are no matches, undefined is returned.

• string string to check for prefixes, must be a string.
• checkpointChar (null, optional) character used to separate potential prefixes. When set to null, every possible prefix is considered.
• reverse (false, optional) set to true to reverse the string before searching.

trie.hasWithCheckpoints(string, [checkpointChar], [reverse])

Used to check if any key matches relevant prefixes from string. Returns a boolean

• string string to check for prefixes, must be a string.
• checkpointChar (null, optional) character used to separate potential prefixes. When set to null, every possible prefix is considered.
• reverse (false, optional) set to true to reverse the string before searching.

Example

const ExactTrie = require('exact-trie');

// Creating a trie instance
const trie = new ExactTrie({ignoreCase: true}); // `ignoreCase` is `true` by default

// Basic API and exact key matches
trie.put('life', 32);
console.log(trie.has('life')); // prints `true`
console.log(trie.get('life')); // prints `32`
console.log(trie.has('lif'));  // prints `false`
console.log(trie.get('lif'));  // prints `undefined`

// Various values and overwriting
const world = {response: 'world'};
trie.put('hello', world);
console.log(trie.get('hello')); // prints `{ response: 'world' }`
trie.put('hello', 3);
console.log(trie.get('hello')); // prints `3`

// Reversing keys
trie.put('oxygen', 8, true);
console.log(trie.has('oxygen'));               // prints `false`
console.log(trie.has('negyxo'));               // prints `true`
console.log(trie.has('oxygen', true)); // prints `true`

// Matching with checkpoints
trie.put('tim', 'Name is Tim');
trie.put('tim.kuzh', 'Tim Kuzh is the name');
console.log(trie.getWithCheckpoints('tim.kuzh', '.')); // prints `Tim Kuzh is the name`
console.log(trie.getWithCheckpoints('tim.cook', '.')); // prints `Name is Tim`

// Matching file extensions
trie.put('tar.gz', 'archive', true);
trie.put('gz', 'gzipped file', true);
console.log(trie.getWithCheckpoints('MyArchive.tar.gz', '.', true));
// -> prints `archive`
console.log(trie.getWithCheckpoints('DataSet.gz', '.', true));
// -> prints `gzipped file`