From 9790d1a45f475f61642c9dedd24c8db6638fcd7f Mon Sep 17 00:00:00 2001
From: Sam Xie <sam@samxie.me>
Date: Mon, 16 Jun 2025 17:48:31 -0700
Subject: [PATCH 1/2] Remove CC-BY-SA-3.0 license by replacing the
 implementation of levenshtein

---
 context.go     |  4 +++-
 go.mod         |  9 +++++++--
 go.sum         |  2 ++
 levenshtein.go | 39 ---------------------------------------
 4 files changed, 12 insertions(+), 42 deletions(-)
 delete mode 100644 levenshtein.go

diff --git a/context.go b/context.go
index 6a4989f6..193b080f 100644
--- a/context.go
+++ b/context.go
@@ -8,6 +8,8 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+
+	"github.com/agnivade/levenshtein"
 )
 
 // Path records the nodes and parsed values from the current command-line.
@@ -1134,7 +1136,7 @@ func findPotentialCandidates(needle string, haystack []string, format string, ar
 	}
 	closestCandidates := []string{}
 	for _, candidate := range haystack {
-		if strings.HasPrefix(candidate, needle) || levenshtein(candidate, needle) <= 2 {
+		if strings.HasPrefix(candidate, needle) || levenshtein.ComputeDistance(candidate, needle) <= 2 {
 			closestCandidates = append(closestCandidates, fmt.Sprintf("%q", candidate))
 		}
 	}
diff --git a/go.mod b/go.mod
index 411174db..c5faa18b 100644
--- a/go.mod
+++ b/go.mod
@@ -5,6 +5,11 @@ require (
 	github.com/alecthomas/repr v0.4.0
 )
 
-require github.com/hexops/gotextdiff v1.0.3 // indirect
+require (
+	github.com/agnivade/levenshtein v1.2.1 // indirect
+	github.com/hexops/gotextdiff v1.0.3 // indirect
+)
+
+go 1.21
 
-go 1.20
+toolchain go1.24.0
diff --git a/go.sum b/go.sum
index f571a34a..16e87e49 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+github.com/agnivade/levenshtein v1.2.1 h1:EHBY3UOn1gwdy/VbFwgo4cxecRznFk7fKWN1KOX7eoM=
+github.com/agnivade/levenshtein v1.2.1/go.mod h1:QVVI16kDrtSuwcpd0p1+xMC6Z/VfhtCyDIjcwga4/DU=
 github.com/alecthomas/assert/v2 v2.11.0 h1:2Q9r3ki8+JYXvGsDyBXwH3LcJ+WK5D0gc5E8vS6K3D0=
 github.com/alecthomas/assert/v2 v2.11.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
 github.com/alecthomas/repr v0.4.0 h1:GhI2A8MACjfegCPVq9f1FLvIBS+DrQ2KQBFZP1iFzXc=
diff --git a/levenshtein.go b/levenshtein.go
deleted file mode 100644
index 6837d6c3..00000000
--- a/levenshtein.go
+++ /dev/null
@@ -1,39 +0,0 @@
-package kong
-
-import "unicode/utf8"
-
-// https://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Levenshtein_distance#Go
-// License: https://creativecommons.org/licenses/by-sa/3.0/
-func levenshtein(a, b string) int {
-	f := make([]int, utf8.RuneCountInString(b)+1)
-
-	for j := range f {
-		f[j] = j
-	}
-
-	for _, ca := range a {
-		j := 1
-		fj1 := f[0] // fj1 is the value of f[j - 1] in last iteration
-		f[0]++
-		for _, cb := range b {
-			mn := min(f[j]+1, f[j-1]+1) // delete & insert
-			if cb != ca {
-				mn = min(mn, fj1+1) // change
-			} else {
-				mn = min(mn, fj1) // matched
-			}
-
-			fj1, f[j] = f[j], mn // save f[j] to fj1(j is about to increase), update f[j] to mn
-			j++
-		}
-	}
-
-	return f[len(f)-1]
-}
-
-func min(a, b int) int { //nolint:predeclared
-	if a <= b {
-		return a
-	}
-	return b
-}

From c8cddd2b1eb02f65590f25e761b295f5cdef28f1 Mon Sep 17 00:00:00 2001
From: Sam Xie <sam@samxie.me>
Date: Mon, 16 Jun 2025 17:51:25 -0700
Subject: [PATCH 2/2] go mod tidy

---
 go.mod | 8 ++------
 go.sum | 4 ++++
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/go.mod b/go.mod
index c5faa18b..277fcf92 100644
--- a/go.mod
+++ b/go.mod
@@ -1,15 +1,11 @@
 module github.com/alecthomas/kong
 
 require (
+	github.com/agnivade/levenshtein v1.2.1
 	github.com/alecthomas/assert/v2 v2.11.0
 	github.com/alecthomas/repr v0.4.0
 )
 
-require (
-	github.com/agnivade/levenshtein v1.2.1 // indirect
-	github.com/hexops/gotextdiff v1.0.3 // indirect
-)
+require github.com/hexops/gotextdiff v1.0.3 // indirect
 
 go 1.21
-
-toolchain go1.24.0
diff --git a/go.sum b/go.sum
index 16e87e49..848bfba3 100644
--- a/go.sum
+++ b/go.sum
@@ -4,5 +4,9 @@ github.com/alecthomas/assert/v2 v2.11.0 h1:2Q9r3ki8+JYXvGsDyBXwH3LcJ+WK5D0gc5E8v
 github.com/alecthomas/assert/v2 v2.11.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
 github.com/alecthomas/repr v0.4.0 h1:GhI2A8MACjfegCPVq9f1FLvIBS+DrQ2KQBFZP1iFzXc=
 github.com/alecthomas/repr v0.4.0/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
+github.com/arbovm/levenshtein v0.0.0-20160628152529-48b4e1c0c4d0 h1:jfIu9sQUG6Ig+0+Ap1h4unLjW6YQJpKZVmUzxsD4E/Q=
+github.com/arbovm/levenshtein v0.0.0-20160628152529-48b4e1c0c4d0/go.mod h1:t2tdKJDJF9BV14lnkjHmOQgcvEKgtqs5a1N3LNdJhGE=
+github.com/dgryski/trifles v0.0.0-20230903005119-f50d829f2e54 h1:SG7nF6SRlWhcT7cNTs5R6Hk4V2lcmLz2NsG2VnInyNo=
+github.com/dgryski/trifles v0.0.0-20230903005119-f50d829f2e54/go.mod h1:if7Fbed8SFyPtHLHbg49SI7NAdJiC5WIA09pe59rfAA=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=