Function applyContentChanges

backend/api/lsp/fs.go:46–80

(uri lsp.DocumentURI, content []byte, changes []lsp.TextDocumentContentChangeEvent)

}

func applyContentChanges(uri lsp.DocumentURI, content []byte, changes []lsp.TextDocumentContentChangeEvent) ([]byte, error) {
	for _, change := range changes {
		if change.Range == nil && change.RangeLength == 0 {
			content = []byte(change.Text) // new full content
			continue
		}
		start, err := offsetForPosition(content, change.Range.Start)
		if err != nil {
			return nil, errors.Wrapf(err, "received textDocument/didChange for invalid position %v on %q", change.Range.Start, uri)
		}

		end, err := offsetForPosition(content, change.Range.End)
		if err != nil {
			return nil, errors.Wrapf(err, "received textDocument/didChange for invalid position %v on %q", change.Range.End, uri)
		}
		if start < 0 || end > len(content) || start > end {
			return nil, errors.Errorf("received textDocument/didChange for out of range position %v on %q", change.Range, uri)
		}

		// Try avoid doing too many allocations, so use bytes.Buffer
		b := &bytes.Buffer{}
		b.Grow(start + len(change.Text) + len(content) - end)
		if _, err := b.Write(content[:start]); err != nil {
			return nil, err
		}
		if _, err := b.WriteString(change.Text); err != nil {
			return nil, err
		}
		if _, err := b.Write(content[end:]); err != nil {
			return nil, err
		}
		content = b.Bytes()
	}
	return content, nil
}

// DidClose notifies the file system that a file was closed.
func (fs *MemFS) DidClose(params *lsp.DidCloseTextDocumentParams) {