Micro diff (µDiff) is a Go library that implements the Myers' diffing algorithm. It aims to provide a minimal API to compute and apply diffs with zero dependencies. It also supports generating diffs in the Unified Format. If you are looking for a way to parse unified diffs, check out sourcegraph/go-diff.
This is merely a copy of the Golang tools internal diff package with a few modifications to export package symbols. All credit goes to the Go authors.
You can import the package using the following command:
go get github.com/aymanbagabas/go-udiff
Generate a unified diff for strings a
and b
.
package main
import (
"fmt"
"github.com/aymanbagabas/go-udiff"
"github.com/aymanbagabas/go-udiff/myers"
)
func main() {
a := "Hello, world!\n"
b := "Hello, Go!\nSay hi to µDiff"
edits := myers.ComputeEdits(a, b)
unified, _ := udiff.ToUnified("a.txt", "b.txt", a, edits)
fmt.Println(unified)
}
--- a.txt
+++ b.txt
@@ -1 +1,2 @@
-Hello, world!
+Hello, Go!
+Say hi to µDiff
\ No newline at end of file
Apply changes to a string.
package main
import (
"fmt"
"github.com/aymanbagabas/go-udiff"
"github.com/aymanbagabas/go-udiff/myers"
)
func main() {
a := "Hello, world!\n"
b := "Hello, Go!\nSay hi to µDiff"
edits := myers.ComputeEdits(a, b)
final, err := udiff.Apply(a, edits)
if err != nil {
panic(err)
}
fmt.Println(final)
}
Hello, Go!
Say hi to µDiff
To get a line-by-line diff and edits:
package main
import (
"fmt"
"github.com/aymanbagabas/go-udiff"
"github.com/aymanbagabas/go-udiff/myers"
)
func main() {
a := "Hello, world!\n"
b := "Hello, Go!\nSay hi to µDiff"
edits := myers.ComputeEdits(a, b)
d, err := udiff.ToUnifiedDiff("a.txt", "b.txt", a, edits)
if err != nil {
panic(err)
}
for _, h := range d.Hunks {
fmt.Printf("hunk: -%d, +%d\n", h.FromLine, h.ToLine)
for _, l := range h.Lines {
fmt.Printf("%s %q\n", l.Kind, l.Content)
}
}
}
hunk: -1, +1
delete "Hello, world!\n"
insert "Hello, Go!\n"
insert "Say hi to µDiff"
- sergi/go-diff No longer reliable. See #123 and #141.
- hexops/gotextdiff Takes the same approach but looks like the project is abandoned.
- sourcegraph/go-diff It doesn't compute diffs. Great package for parsing and printing unified diffs.
Please send any contributions upstream. Pull requests made against the upstream diff package are welcome.
BSD 3-Clause and MIT.