| // Copyright 2019 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package myers |
| |
| import ( |
| "fmt" |
| "strings" |
| |
| "golang.org/x/tools/internal/lsp/diff" |
| "golang.org/x/tools/internal/span" |
| ) |
| |
| func init() { |
| diff.ToUnified = myersToUnified |
| } |
| |
| func ComputeEdits(uri span.URI, before, after string) []diff.TextEdit { |
| u := SplitLines(before) |
| f := SplitLines(after) |
| return myersDiffToEdits(uri, Operations(u, f)) |
| } |
| |
| func myersToUnified(from, to string, before string, edits []diff.TextEdit) string { |
| u := SplitLines(before) |
| ops := myersEditsToDiff(edits) |
| return fmt.Sprint(ToUnified(from, to, u, ops)) |
| } |
| |
| func myersDiffToEdits(uri span.URI, ops []*Op) []diff.TextEdit { |
| edits := make([]diff.TextEdit, 0, len(ops)) |
| for _, op := range ops { |
| s := span.New(uri, span.NewPoint(op.I1+1, 1, 0), span.NewPoint(op.I2+1, 1, 0)) |
| switch op.Kind { |
| case diff.Delete: |
| // Delete: unformatted[i1:i2] is deleted. |
| edits = append(edits, diff.TextEdit{Span: s}) |
| case diff.Insert: |
| // Insert: formatted[j1:j2] is inserted at unformatted[i1:i1]. |
| if content := strings.Join(op.Content, ""); content != "" { |
| edits = append(edits, diff.TextEdit{Span: s, NewText: content}) |
| } |
| } |
| } |
| return edits |
| } |
| |
| func myersEditsToDiff(edits []diff.TextEdit) []*Op { |
| iToJ := 0 |
| ops := make([]*Op, len(edits)) |
| for i, edit := range edits { |
| i1 := edit.Span.Start().Line() - 1 |
| i2 := edit.Span.End().Line() - 1 |
| kind := diff.Insert |
| if edit.NewText == "" { |
| kind = diff.Delete |
| } |
| ops[i] = &Op{ |
| Kind: kind, |
| Content: SplitLines(edit.NewText), |
| I1: i1, |
| I2: i2, |
| J1: i1 + iToJ, |
| } |
| if kind == diff.Insert { |
| iToJ += len(ops[i].Content) |
| } else { |
| iToJ -= i2 - i1 |
| } |
| } |
| return ops |
| } |
