+++ /dev/null
-// 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 diff supports a pluggable diff algorithm.
-package diff
-
-import (
- "sort"
- "strings"
-
- "golang.org/x/tools/internal/span"
-)
-
-// TextEdit represents a change to a section of a document.
-// The text within the specified span should be replaced by the supplied new text.
-type TextEdit struct {
- Span span.Span
- NewText string
-}
-
-// ComputeEdits is the type for a function that produces a set of edits that
-// convert from the before content to the after content.
-type ComputeEdits func(uri span.URI, before, after string) []TextEdit
-
-// SortTextEdits attempts to order all edits by their starting points.
-// The sort is stable so that edits with the same starting point will not
-// be reordered.
-func SortTextEdits(d []TextEdit) {
- // Use a stable sort to maintain the order of edits inserted at the same position.
- sort.SliceStable(d, func(i int, j int) bool {
- return span.Compare(d[i].Span, d[j].Span) < 0
- })
-}
-
-// ApplyEdits applies the set of edits to the before and returns the resulting
-// content.
-// It may panic or produce garbage if the edits are not valid for the provided
-// before content.
-func ApplyEdits(before string, edits []TextEdit) string {
- // Preconditions:
- // - all of the edits apply to before
- // - and all the spans for each TextEdit have the same URI
- if len(edits) == 0 {
- return before
- }
- _, edits, _ = prepareEdits(before, edits)
- after := strings.Builder{}
- last := 0
- for _, edit := range edits {
- start := edit.Span.Start().Offset()
- if start > last {
- after.WriteString(before[last:start])
- last = start
- }
- after.WriteString(edit.NewText)
- last = edit.Span.End().Offset()
- }
- if last < len(before) {
- after.WriteString(before[last:])
- }
- return after.String()
-}
-
-// LineEdits takes a set of edits and expands and merges them as necessary
-// to ensure that there are only full line edits left when it is done.
-func LineEdits(before string, edits []TextEdit) []TextEdit {
- if len(edits) == 0 {
- return nil
- }
- c, edits, partial := prepareEdits(before, edits)
- if partial {
- edits = lineEdits(before, c, edits)
- }
- return edits
-}
-
-// prepareEdits returns a sorted copy of the edits
-func prepareEdits(before string, edits []TextEdit) (*span.TokenConverter, []TextEdit, bool) {
- partial := false
- c := span.NewContentConverter("", []byte(before))
- copied := make([]TextEdit, len(edits))
- for i, edit := range edits {
- edit.Span, _ = edit.Span.WithAll(c)
- copied[i] = edit
- partial = partial ||
- edit.Span.Start().Offset() >= len(before) ||
- edit.Span.Start().Column() > 1 || edit.Span.End().Column() > 1
- }
- SortTextEdits(copied)
- return c, copied, partial
-}
-
-// lineEdits rewrites the edits to always be full line edits
-func lineEdits(before string, c *span.TokenConverter, edits []TextEdit) []TextEdit {
- adjusted := make([]TextEdit, 0, len(edits))
- current := TextEdit{Span: span.Invalid}
- for _, edit := range edits {
- if current.Span.IsValid() && edit.Span.Start().Line() <= current.Span.End().Line() {
- // overlaps with the current edit, need to combine
- // first get the gap from the previous edit
- gap := before[current.Span.End().Offset():edit.Span.Start().Offset()]
- // now add the text of this edit
- current.NewText += gap + edit.NewText
- // and then adjust the end position
- current.Span = span.New(current.Span.URI(), current.Span.Start(), edit.Span.End())
- } else {
- // does not overlap, add previous run (if there is one)
- adjusted = addEdit(before, adjusted, current)
- // and then remember this edit as the start of the next run
- current = edit
- }
- }
- // add the current pending run if there is one
- return addEdit(before, adjusted, current)
-}
-
-func addEdit(before string, edits []TextEdit, edit TextEdit) []TextEdit {
- if !edit.Span.IsValid() {
- return edits
- }
- // if edit is partial, expand it to full line now
- start := edit.Span.Start()
- end := edit.Span.End()
- if start.Column() > 1 {
- // prepend the text and adjust to start of line
- delta := start.Column() - 1
- start = span.NewPoint(start.Line(), 1, start.Offset()-delta)
- edit.Span = span.New(edit.Span.URI(), start, end)
- edit.NewText = before[start.Offset():start.Offset()+delta] + edit.NewText
- }
- if start.Offset() >= len(before) && start.Line() > 1 && before[len(before)-1] != '\n' {
- // after end of file that does not end in eol, so join to last line of file
- // to do this we need to know where the start of the last line was
- eol := strings.LastIndex(before, "\n")
- if eol < 0 {
- // file is one non terminated line
- eol = 0
- }
- delta := len(before) - eol
- start = span.NewPoint(start.Line()-1, 1, start.Offset()-delta)
- edit.Span = span.New(edit.Span.URI(), start, end)
- edit.NewText = before[start.Offset():start.Offset()+delta] + edit.NewText
- }
- if end.Column() > 1 {
- remains := before[end.Offset():]
- eol := strings.IndexRune(remains, '\n')
- if eol < 0 {
- eol = len(remains)
- } else {
- eol++
- }
- end = span.NewPoint(end.Line()+1, 1, end.Offset()+eol)
- edit.Span = span.New(edit.Span.URI(), start, end)
- edit.NewText = edit.NewText + remains[:eol]
- }
- edits = append(edits, edit)
- return edits
-}
projects / dotfiles / .git / blobdiff