isabella232 / fuzzy-string-match

fuzzy string matching library for ruby

What is fuzzy-string-match

• fuzzy-string-match is a fuzzy string matching library for ruby.
• It is fast. ( written in C with RubyInline )
• It supports only Jaro-Winkler distance algorithm.
• This program was ported by hand from lucene-3.0.2. (lucene is Java product)
• If you want to add another string distance algorithm, please fork it on github and port by yourself.

The reason why i developed fuzzy-string-match

• I tried amatch-0.2.5, but it contains some issues.
  1. memory leaks.
  2. I felt difficult to maintain it.
• So, I decide to create another gem by porting lucene-3.0.x.

Installing

gem install fuzzy-string-match

Installing (pure ruby version)

gem install fuzzy-string-match_pure

Features

• Calculate Jaro-Winkler distance of two strings.
  • Pure ruby version can handle both ASCII and UTF8 strings. (and slow)
  • Native version can only ASCII strings. (but it is fast)

Sample code

Native version

require 'fuzzystringmatch'
jarow = FuzzyStringMatch::JaroWinkler.create( :native )
p jarow.getDistance(  "jones",      "johnson" )

Pure ruby version

require 'fuzzystringmatch'
jarow = FuzzyStringMatch::JaroWinkler.create( :pure )
p jarow.getDistance(  "jones",      "johnson" )
p jarow.getDistance(  "ああ",        "あい"        )

Sample on irb

irb(main):001:0> require 'fuzzystringmatch'
require 'fuzzystringmatch'
=> true

irb(main):002:0> jarow = FuzzyStringMatch::JaroWinkler.create( :native )
jarow = FuzzyStringMatch::JaroWinkler.create( :native )
=> #<FuzzyStringMatch::JaroWinklerNative:0x000001011b0010>

irb(main):003:0> jarow.getDistance( "al",        "al"        )
jarow.getDistance( "al",        "al"        )
=> 1.0

irb(main):004:0> jarow.getDistance( "dixon",     "dicksonx"  )
jarow.getDistance( "dixon",     "dicksonx"  )
=> 0.8133333333333332

Benchmarks

$ rake bench
ruby ./benchmark/vs_amatch.rb
 --- 
 --- Each match functions will be called 1Mega times. --- 
 --- 
[Amatch]
      user     system      total        real
  1.160000   0.050000   1.210000 (  1.218259)
[this Module (pure)]
      user     system      total        real
 39.940000   0.160000  40.100000 ( 40.542448)
[this Module (native)]
      user     system      total        real
  0.480000   0.000000   0.480000 (  0.484187)

Requires

for CRuby

• RubyInline
• Ruby 1.9.1 or higher

for JRuby

• JRuby 1.6.6 or higher

Author

• Copyright (C) Kiyoka Nishiyama [email protected]
• I ported from java source code of lucene-3.0.2.

See also

• http://en.wikipedia.org/wiki/Jaro–Winkler_distance
• http://lucene.apache.org/
• http://github.com/naoya/perl-text-jarowinkler

License

• Apache 2.0 LICENSE