Text Metrics

The library provides efficient implementations of various strings metric algorithms. It works with strict Text values.

The current version of the package implements:

• Levenshtein distance
• Normalized Levenshtein distance
• Damerau-Levenshtein distance
• Normalized Damerau-Levenshtein distance
• Hamming distance
• Jaro distance
• Jaro-Winkler distance
• Overlap coefficient
• Jaccard similarity coefficient

Comparison with the edit-distance package

There is edit-distance package whose scope overlaps with the scope of this package. The differences are:

• edit-distance allows to specify costs for every operation when calculating Levenshtein distance (insertion, deletion, substitution, and transposition). This is rarely needed though in real-world applications, IMO.

• edit-distance only provides Levenshtein distance, text-metrics aims to provide implementations of most string metrics algorithms.

• edit-distance works on Strings, while text-metrics works on strict Text values.

Implementation

Although we originally used C for speed, currently all functions are pure Haskell tuned for performance. See this blog post for more info.

License

Copyright © 2016–2018 Mark Karpov

Distributed under BSD 3 clause license.