A trie data structure implementation for ruby. Currently, it’s a pretty minimal implementation. I’ve only implemented Trie#[], Trie#[]=, and Trie#delete so far. It’s also fairly naive: There’s plenty of room for optimization I’m sure, especially in key character sibling storage. (Currently a just linked list.) However, it does manage to be a bit faster than a native ruby Hash for similar keys.

Usage

Compile the extension:

ruby extconf.rb make

Code:

require ‘trie’

t = Trie.new t = “value” t # => “value”

t.children(“partial key”) will return all values for all keys that match the partial key

t = 1 t = 2 t = 3 t = 4

by default assigning multiple values to the same object will add them to an array. t = 1 t = 2 will return for t => [1,2]

t.children(“go”) => [1,2,3]

t.each(“partial key”) will yield to the given block all values that are matched by the partial key t.each(“go”) {|v| puts v } => prints 1, 2 & 3

Levenshtein search

t.levenshtein_search(“go”, 2) {|value| puts value} - will print all values for the words in the trie that have 2 distance from the search word Eg. 1 2 3

Bugs

I’m sure there are plenty!

License

This software is copyright © 2008 Matt Freels

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.