org.webjars.npm:trie-search

Trie-Search

A Trie is a data structure designed for rapid reTRIEval of objects. This was designed for use with a typeahead search.

Most Trie implementations in NPM right now only let you add and then determine if a word or phrase exists in the Trie.

This data structure allows you to map keys to objects, allowing rapid search of whatever dictionary you like.

Note: as of now, keys are split along word boundaries! For example, if your key is 'the quick brown fox', the TrieSearch will be searchable by 'the', 'quick', 'brown', or 'fox'.

Setup

new TrieSearch(keyFields, options)

keyFields: a single string or an array of strings representing what fields on added objects are to be used as keys for the trie search.

options: settings to provide to the TrieSearch. To be expanded as functionality grows, but current structure is:

{
  min: 1,  // Minimum length of a key to store and search. By default this is 1, but you might improve performance by using 2 or 3
  ignoreCase: true,
  indexField: undefined, // Defaults to undefined. If specified, determines which rows are unique when using get().
  splitOnRegEx: /\s/g // Default regular expression to split all keys into tokens. By default this is any whitespace. Set to 'false' if you have whitespace in your keys!
}

Supported Types

All values are converted to a Javascript String object via the .toString() method before inserted into the Trie structure.

So the values '1234' and 1234 are functionally equivalent.

Example 1 (from Object)

var TrieSearch = require('trie-search');

var object = {
  'andrew': {age: 21},
  'andy': {age: 37},
  'andrea': {age: 25},
  'annette': {age: 67},
};

var ts = new TrieSearch();

ts.addFromObject(object);

ts.get('a'); // Returns all 4 items above.
ts.get('an'); // Returns all 4 items above.
ts.get('and'); // Returns all 3 items above that begin with 'and'
ts.get('andr'); // Returns all 2 items above that begin with 'andr'
ts.get('andre'); // Returns only andrew.

Example 2 (add items individually or from Array)

var TrieSearch = require('trie-search');

var objects = [
  {name: 'andrew', age: 21},
  {name: 'andy', age: 37},
  {name: 'andrea', age: 25},
  {name: 'annette', age: 67}
];

var ts = new TrieSearch('name');

objects.forEach(ts.add.bind(ts));

ts.get('a'); // Returns all 4 items above.
ts.get('an'); // Returns all 4 items above.
ts.get('and'); // Returns all 3 items above that begin with 'and'
ts.get('andr'); // Returns all 2 items above that begin with 'andr'
ts.get('andre'); // Returns only andrew.

Example 2 (deep key lookup)

var TrieSearch = require('trie-search');

var objects = [
  {name: 'andrew', details: {age: 21}},
  {name: 'andy', details: {age: 37}},
  {name: 'andrea', details: {age: 25}},
  {name: 'annette', details: {age: 67}}
];

var ts = new TrieSearch([
  'name', // Searches `object.name`
  ['details', 'age'] // `Search object.details.age`
]);

objects.forEach(ts.add.bind(ts));

ts.get('21'); // Returns 'andrew' which has age of 21

Example 3 (options.min == 3)

var TrieSearch = require('trie-search', {min: 3});

var objects = [
  {name: 'andrew', age: 21},
  {name: 'andy', age: 37},
  {name: 'andrea', age: 25},
  {name: 'annette', age: 67}
];

var ts = new TrieSearch('name');

objects.forEach(ts.add.bind(ts));

ts.get('a'); // Returns empty array, too short of search
ts.get('an'); // Returns empty array, too short of search
ts.get('and'); // Returns all 3 items above that begin with 'and'
ts.get('andr'); // Returns all 2 items above that begin with 'andr'
ts.get('andre'); // Returns only andrew.

Example 4 (options.indexField = 'ix')

By default, the HashArray object (which TrieSearch uses) does not - for the sake of speed - verify object uniqueness by the object itself, but instead by a field on that object.

As a result, in order for get() to be used with multiple words, it is important that a field is used to identify each record in the TrieSearch, similar to a index in a database.

var TrieSearch = require('trie-search', {min: 3, indexField: 'ix'});

var objects = [
  {ix: 1, name: 'andrew', location: 'sweden', age: 21},
  {ix: 2, name: 'andrew', location: 'brussels', age: 37},
  {ix: 3, name: 'andrew', location: 'johnsonville', age: 25}
];

var ts = new TrieSearch('name');

objects.forEach(ts.add.bind(ts));

ts.get('andrew');        // Returns all items
ts.get('andrew sweden'); // Returns all items without indexField. Returns only andrew in sweden with indexField.

Example 5 (get() OR of multiple phrases)

var TrieSearch = require('trie-search');

var objects = [
  {name: 'andrew', age: 21, zip: 60600},
  {name: 'andy', age: 37, zip: 60601},
  {name: 'andrea', age: 25, zip: 60602},
  {name: 'joseph', age: 67, zip: 60603}
];

var ts = new TrieSearch(['name', 'age', 'zip']);

objects.forEach(ts.add.bind(ts));

ts.get('andre'); // Returns only andrew.
ts.get(['andre', '25']); // Returns andrew AND andrea
ts.get(['andre', 'jos']); // Returns andrew AND joseph
ts.get(['21', '67']); // Returns andrew AND joseph
ts.get(['21', '60603']); // Returns andrew AND joseph

Testing

>mocha

START

  ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․

  54 passing (25ms)

License

The MIT License (MIT)

Copyright (c) 2014 Joshua Jung

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.