From 8799790a036a7b967c7cef8cc937cefd5d09c8db Mon Sep 17 00:00:00 2001 From: Rohit Subedi Date: Sun, 18 Oct 2020 22:01:45 +0200 Subject: [PATCH] Initial commit --- .gitignore | 15 +++++++ .golangci.yml | 46 +++++++++++++++++++ .travis.yml | 19 ++++++++ LICENSE | 21 +++++++++ Makefile | 7 +++ README.md | 1 + go.mod | 5 +++ go.sum | 11 +++++ levenshtein.go | 71 ++++++++++++++++++++++++++++++ test/levenshtein_test.go | 95 ++++++++++++++++++++++++++++++++++++++++ 10 files changed, 291 insertions(+) create mode 100644 .gitignore create mode 100644 .golangci.yml create mode 100644 .travis.yml create mode 100644 LICENSE create mode 100644 Makefile create mode 100644 README.md create mode 100644 go.mod create mode 100644 go.sum create mode 100644 levenshtein.go create mode 100644 test/levenshtein_test.go diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..66fd13c --- /dev/null +++ b/.gitignore @@ -0,0 +1,15 @@ +# Binaries for programs and plugins +*.exe +*.exe~ +*.dll +*.so +*.dylib + +# Test binary, built with `go test -c` +*.test + +# Output of the go coverage tool, specifically when used with LiteIDE +*.out + +# Dependency directories (remove the comment below to include it) +# vendor/ diff --git a/.golangci.yml b/.golangci.yml new file mode 100644 index 0000000..1cdabc6 --- /dev/null +++ b/.golangci.yml @@ -0,0 +1,46 @@ +run: + concurrency: 4 + tests: true + +linters-settings: + errcheck: + check-type-assertions: false + check-blank: true + govet: + check-shadowing: true + golint: + min-confidence: 0.8 + goimports: + local-prefixes: github.com/rohitsubedi/levenshtein + gocyclo: + min-complexity: 10 + maligned: + suggest-new: true + dupl: + threshold: 75 + goconst: + min-len: 3 + min-occurrences: 3 + depguard: + list-type: blacklist + include-go-root: false + misspell: + locale: US + ignore-words: + - someword + lll: + line-length: 120 + tab-width: 1 + unused: + check-exported: false + unparam: + check-exported: false + nakedret: + max-func-lines: 20 + prealloc: + simple: true + range-loops: true # Report preallocation suggestions on range loops, true by default + for-loops: false # Report preallocation suggestions on for loops, false by default +linters: + enable-all: true + fast: false diff --git a/.travis.yml b/.travis.yml new file mode 100644 index 0000000..65c2f36 --- /dev/null +++ b/.travis.yml @@ -0,0 +1,19 @@ +language: go + +go_import_path: github.com/rohitsubedi/levenshtein + +before_install: + - export GO111MODULE=on + +go: + - 1.13.x + - 1.14.x + - 1.15.x + - tip + +install: + - go get github.com/stretchr/testify@v1.6.1 + - go get github.com/golangci/golangci-lint/cmd/golangci-lint + +script: + - make check diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..9f88fb8 --- /dev/null +++ b/LICENSE @@ -0,0 +1,21 @@ +MIT License + +Copyright (c) 2020 Rohit Subedi + +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. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..d7100b3 --- /dev/null +++ b/Makefile @@ -0,0 +1,7 @@ +check: test lint + +test: ## Runs the unit tests. + @go test $(PKG_NAME) + +lint: ## Runs the linter. + @golangci-lint run diff --git a/README.md b/README.md new file mode 100644 index 0000000..6244db3 --- /dev/null +++ b/README.md @@ -0,0 +1 @@ +# levenshtein \ No newline at end of file diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..1ad945e --- /dev/null +++ b/go.mod @@ -0,0 +1,5 @@ +module github.com/rohitsubedi/levenshtein + +go 1.15 + +require github.com/stretchr/testify v1.6.1 diff --git a/go.sum b/go.sum new file mode 100644 index 0000000..afe7890 --- /dev/null +++ b/go.sum @@ -0,0 +1,11 @@ +github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8= +github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM= +github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= +github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME= +github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0= +github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= +gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo= +gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= diff --git a/levenshtein.go b/levenshtein.go new file mode 100644 index 0000000..1670c5f --- /dev/null +++ b/levenshtein.go @@ -0,0 +1,71 @@ +package levenshtein + +const increment = 1 + +func GetLevenshteinDistance(str1, str2 []rune, caseSensitive bool) int { + rows := len(str2) + cols := len(str1) + + // If one of the given string is empty, Levenshtein distance is the max length of two string + if rows == 0 || cols == 0 { + return max(rows, cols) + } + + // Minimize space complexity. O(min(str1, str2) instead of O(str1) + if cols > rows { + rows, cols = cols, rows + str1, str2 = str2, str1 + } + + dp := make([]uint16, cols+increment) + + for i := 0; i <= rows; i++ { + left := uint16(i) + + for j := 1; j <= cols; j++ { + if i == 0 { + dp[j], left = uint16(j), dp[j] + } else { + diag, top := dp[j-1], dp[j] + + if !isSameChar(str2[i-1], str1[j-1], caseSensitive) { + diag = min(left, min(diag, top)) + uint16(increment) + } + + dp[j-1], left = left, diag + } + } + + dp[cols] = left + } + + return int(dp[cols]) +} + +func isSameChar(c1, c2 rune, caseSensitive bool) bool { + if c1 == c2 { + return true + } + + if caseSensitive { + return false + } + + return c1 == c2-32 || c1-32 == c2 +} + +func min(a, b uint16) uint16 { + if a <= b { + return a + } + + return b +} + +func max(a, b int) int { + if a >= b { + return a + } + + return b +} diff --git a/test/levenshtein_test.go b/test/levenshtein_test.go new file mode 100644 index 0000000..1d726bd --- /dev/null +++ b/test/levenshtein_test.go @@ -0,0 +1,95 @@ +package test_test + +import ( + "strings" + "testing" + + "github.com/stretchr/testify/assert" + + "github.com/rohitsubedi/levenshtein" +) + +func TestMinOperationToConvertOneStringToAnother1(t *testing.T) { + destString := "DE-2341-00001" + // For same strings + minOperation := levenshtein.GetLevenshteinDistance([]rune(destString), []rune(destString), false) + assert.Equal(t, 0, minOperation) + // For same strings but different case(lower case) + minOperation = levenshtein.GetLevenshteinDistance([]rune(strings.ToLower(destString)), []rune(destString), false) + assert.Equal(t, 0, minOperation) + // For string with 1 char missing + minOperation = levenshtein.GetLevenshteinDistance([]rune("D-2341-00001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-231-00001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-2341-0001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-234100001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + // For string with 1 extra char + minOperation = levenshtein.GetLevenshteinDistance([]rune("DEE-2341-00001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-23441-00001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-2341-000001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-2341--00001"), []rune(destString), false) + assert.Equal(t, 1, minOperation) + // For string with 2 char missing + minOperation = levenshtein.GetLevenshteinDistance([]rune("-2341-00001"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-21-00001"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-2341-000"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE234100001"), []rune(destString), false) + assert.Equal(t, 2, minOperation) +} + +func TestMinOperationToConvertOneStringToAnother2(t *testing.T) { + destString := "DE-2341-00001" + // For string with 2 extra char + minOperation := levenshtein.GetLevenshteinDistance([]rune("DEE--2341-00001"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-2344-1-00001"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-2341-0000199"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE--2341--00001"), []rune(destString), false) + assert.Equal(t, 2, minOperation) + // For string with more than 2 char missing + minOperation = levenshtein.GetLevenshteinDistance([]rune("2341-00001"), []rune(destString), false) + assert.Equal(t, 3, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE-34-001"), []rune(destString), false) + assert.Equal(t, 4, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DE34-001"), []rune(destString), false) + assert.Equal(t, 5, minOperation) + // For string with more than 2 extra char + minOperation = levenshtein.GetLevenshteinDistance([]rune("DEE--23341-00001"), []rune(destString), false) + assert.Equal(t, 3, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DEE--23341-000001"), []rune(destString), false) + assert.Equal(t, 4, minOperation) + minOperation = levenshtein.GetLevenshteinDistance([]rune("DEE--233414-000001"), []rune(destString), false) + assert.Equal(t, 5, minOperation) + // Test case sensitive + minOperation = levenshtein.GetLevenshteinDistance([]rune("ROHIT"), []rune("rohit"), true) + assert.Equal(t, 5, minOperation) + // Test case in sensitive + minOperation = levenshtein.GetLevenshteinDistance([]rune("ROHIT"), []rune("rohit"), false) + assert.Equal(t, 0, minOperation) + // UTF-8 characters + minOperation = levenshtein.GetLevenshteinDistance([]rune("rohit"), []rune("röhit"), false) + assert.Equal(t, 1, minOperation) + // Test empty string + minOperation = levenshtein.GetLevenshteinDistance([]rune("ROHIT"), []rune(""), true) + assert.Equal(t, 5, minOperation) + // Test empty string + minOperation = levenshtein.GetLevenshteinDistance([]rune("ö"), []rune(""), true) + assert.Equal(t, 1, minOperation) + // Test case in sensitive + minOperation = levenshtein.GetLevenshteinDistance([]rune("ROHIT"), []rune("tihor"), false) + assert.Equal(t, 4, minOperation) + // UTF-8 characters same + minOperation = levenshtein.GetLevenshteinDistance([]rune("röhit"), []rune("röhit"), false) + assert.Equal(t, 0, minOperation) +}