edits

A collection of edit distance algorithms in Crystal.

Includes Levenshtein, Restricted Edit (Optimal Alignment) and Damerau-Levenshtein distances, and Jaro and Jaro-Winkler similarity.

Installation

Add this to your application's shard.yml:

dependencies:
  edits:
    github: tcrouch/edits.cr

Usage

require "edits"

Levenshtein

Edit distance, taking into account deletion, addition and substitution.

Edits::Levenshtein.distance "raked", "bakers"
# => 3
Edits::Levenshtein.distance "iota", "atom"
# => 4
Edits::Levenshtein.distance "acer", "earn"
# => 4

# Max distance
Edits::Levenshtein.distance "iota", "atom", 2
# => 2
Edits::Levenshtein.most_similar "atom", ["atlas", "tram", "rota", "racer"]
# => "atlas"

Restricted Edit (Optimal Alignment)

Edit distance, accounting for deletion, addition, substitution and transposition (two adjacent characters are swapped). This variant is restricted by the condition that no sub-string is edited more than once.

Edits::RestrictedEdit.distance "raked", "bakers"
# => 3
Edits::RestrictedEdit.distance "iota", "atom"
# => 3
Edits::RestrictedEdit.distance "acer", "earn"
# => 4

# Max distance
Edits::RestrictedEdit.distance "iota", "atom", 2
# => 2
Edits::RestrictedEdit.most_similar "atom", ["iota", "tome", "mown", "tame"]
# => "tome"

Damerau-Levenshtein

Edit distance, accounting for deletions, additions, substitution and transposition (two adjacent characters are swapped).

Edits::DamerauLevenshtein.distance "raked", "bakers"
# => 3
Edits::DamerauLevenshtein.distance "iota", "atom"
# => 3
Edits::DamerauLevenshtein.distance "acer", "earn"
# => 3

Jaro & Jaro-Winkler

Edits::Jaro.similarity "information", "informant"
# => 0.90235690235690236
Edits::Jaro.distance "information", "informant"
# => 0.097643097643097643

Edits::JaroWinkler.similarity "information", "informant"
# => 0.94141414141414137
Edits::JaroWinkler.distance "information", "informant"
# => 0.05858585858585863

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• [tcrouch] Tom Crouch - creator, maintainer