sclass AudioLine {
  Mixer mixer;
  Line.Info lineInfo;
  
  *() {}
  *(Mixer *mixer, Line.Info *lineInfo) {}
  
  Line open() {
    ret mixer.getLine(lineInfo);
  }
}

static L<AudioLine> allAudioLines() {
  ret concatMap(listAudioDevices(), f allAudioLines);
}

static L<AudioLine> allAudioLines(Mixer m) {
  new L<AudioLine> l;
  for (Line.Info lineInfo : concatLists(
    asList(m.getTargetLineInfo()),
    asList(m.getSourceLineInfo())))
    l.add(new AudioLine(m, lineInfo));
  ret l;
}