package manifest import ( "bytes" "fmt" "io" ) // try parsing as a 2822 manifest, but fallback to line-based if that fails func Parse(reader io.Reader) (*Manifest2822, error) { buf := &bytes.Buffer{} // try parsing as 2822, but also copy back into a new buffer so that if it fails, we can re-parse as line-based manifest, err2822 := Parse2822(io.TeeReader(reader, buf)) if err2822 != nil { manifest, err := ParseLineBased(buf) if err != nil { return nil, fmt.Errorf("cannot parse manifest in either format:\nRFC 2822 error: %v\nLine-based error: %v", err2822, err) } return manifest, nil } return manifest, nil }