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().
}
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)
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(function (item) {
ts.add(item);
});
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 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(function (item) {
ts.add(item);
});
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(function (item) {
ts.add(item);
});
ts.get('andrew'); // Returns all items
ts.get('andrew sweden'); // Returns all items without indexField. Returns only andrew in sweden with indexField.
Testing
>mocha
START
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37 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.
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.