levenshtein

Go package to calculate the Levenshtein Distance

The library is fully capable of working with non-ascii strings. But the strings are not normalized. That is left as a user-dependant use case. Please normalize the strings before passing it to the library if you have such a requirement.

• https://blog.golang.org/normalization

Limitation

As a performance optimization, the library can handle strings only up to 65536 characters (runes). If you need to handle strings larger than that, please pin to version 1.0.3.

Install

go get github.com/agnivade/levenshtein

Example

package main

import (
	"fmt"
	"github.com/agnivade/levenshtein"
)

func main() {
	s1 := "kitten"
	s2 := "sitting"
	distance := levenshtein.ComputeDistance(s1, s2)
	fmt.Printf("The distance between %s and %s is %d.\n", s1, s2, distance)
	// Output:
	// The distance between kitten and sitting is 3.
}

Benchmarks

goos: darwin
goarch: arm64
pkg: github.com/agnivade/levenshtein
cpu: Apple M4
                      │  bench.out  │
                      │   sec/op    │
Simple/ASCII-10         123.8n ± 0%
Simple/French-10        212.6n ± 1%
Simple/Nordic-10        365.9n ± 0%
Simple/Long_lead-10     224.5n ± 0%
Simple/Long_middle-10   379.9n ± 0%
Simple/Long_trail-10    580.8n ± 0%
Simple/Long_diff-10     8.008µ ± 0%
Simple/Tibetan-10       459.5n ± 0%
geomean                 452.4n

                      │  bench.out   │
                      │     B/op     │
Simple/ASCII-10         0.000 ± 0%
Simple/French-10        0.000 ± 0%
Simple/Nordic-10        0.000 ± 0%
Simple/Long_lead-10     368.0 ± 0%
Simple/Long_middle-10   544.0 ± 0%
Simple/Long_trail-10    576.0 ± 0%
Simple/Long_diff-10     720.0 ± 0%
Simple/Tibetan-10       0.000 ± 0%
geomean                            ¹
¹ summaries must be >0 to compute geomean

                      │  bench.out   │
                      │  allocs/op   │
Simple/ASCII-10         0.000 ± 0%
Simple/French-10        0.000 ± 0%
Simple/Nordic-10        0.000 ± 0%
Simple/Long_lead-10     2.000 ± 0%
Simple/Long_middle-10   2.000 ± 0%
Simple/Long_trail-10    2.000 ± 0%
Simple/Long_diff-10     3.000 ± 0%
Simple/Tibetan-10       0.000 ± 0%
geomean                            ¹
¹ summaries must be >0 to compute geomean

Comparisons with other libraries

github.com/dgryski/trifles

goos: darwin
goarch: arm64
pkg: github.com/agnivade/levenshtein
cpu: Apple M4
                    │   dgryski   │               agniva                │
                    │   sec/op    │   sec/op     vs base                │
All/case=ASCII-10     288.4n ± 0%   123.9n ± 1%  -57.05% (p=0.000 n=20)
All/case=French-10    518.8n ± 0%   211.7n ± 1%  -59.20% (p=0.000 n=20)
All/case=Nordic-10    963.8n ± 0%   369.4n ± 1%  -61.67% (p=0.000 n=20)
All/case=Tibetan-10   795.6n ± 0%   460.1n ± 0%  -42.18% (p=0.000 n=20)
geomean               582.0n        258.4n       -55.60%

                    │  dgryski   │                 agniva                 │
                    │    B/op    │   B/op     vs base                     │
All/case=ASCII-10     96.00 ± 0%   0.00 ± 0%  -100.00% (p=0.000 n=20)
All/case=French-10    128.0 ± 0%    0.0 ± 0%  -100.00% (p=0.000 n=20)
All/case=Nordic-10    192.0 ± 0%    0.0 ± 0%  -100.00% (p=0.000 n=20)
All/case=Tibetan-10   160.0 ± 0%    0.0 ± 0%  -100.00% (p=0.000 n=20)
geomean               139.4                   ?                       ¹ ²
¹ summaries must be >0 to compute geomean
² ratios must be >0 to compute geomean

                    │  dgryski   │                 agniva                  │
                    │ allocs/op  │ allocs/op   vs base                     │
All/case=ASCII-10     1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
All/case=French-10    1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
All/case=Nordic-10    1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
All/case=Tibetan-10   1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
geomean               1.000                    ?                       ¹ ²
¹ summaries must be >0 to compute geomean
² ratios must be >0 to compute geomean

github.com/arbovm/levenshtein

goos: darwin
goarch: arm64
pkg: github.com/agnivade/levenshtein
cpu: Apple M4
                    │   arbovm    │               agniva                │
                    │   sec/op    │   sec/op     vs base                │
All/case=ASCII-10     283.1n ± 1%   123.9n ± 1%  -56.23% (p=0.000 n=20)
All/case=French-10    516.4n ± 0%   211.7n ± 1%  -59.01% (p=0.000 n=20)
All/case=Nordic-10    978.9n ± 0%   369.4n ± 1%  -62.26% (p=0.000 n=20)
All/case=Tibetan-10   804.9n ± 0%   460.1n ± 0%  -42.84% (p=0.000 n=20)
geomean               582.6n        258.4n       -55.65%

                    │   arbovm   │                 agniva                 │
                    │    B/op    │   B/op     vs base                     │
All/case=ASCII-10     96.00 ± 0%   0.00 ± 0%  -100.00% (p=0.000 n=20)
All/case=French-10    128.0 ± 0%    0.0 ± 0%  -100.00% (p=0.000 n=20)
All/case=Nordic-10    192.0 ± 0%    0.0 ± 0%  -100.00% (p=0.000 n=20)
All/case=Tibetan-10   160.0 ± 0%    0.0 ± 0%  -100.00% (p=0.000 n=20)
geomean               139.4                   ?                       ¹ ²
¹ summaries must be >0 to compute geomean
² ratios must be >0 to compute geomean

                    │   arbovm   │                 agniva                  │
                    │ allocs/op  │ allocs/op   vs base                     │
All/case=ASCII-10     1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
All/case=French-10    1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
All/case=Nordic-10    1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
All/case=Tibetan-10   1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=20)
geomean               1.000                    ?                       ¹ ²
¹ summaries must be >0 to compute geomean
² ratios must be >0 to compute geomean