index.js
function cliCompleter(set, done) {
  var exposed = {}

  set.valueOf().forEach(expose)
  set.valueOf().forEach(checkFactory(exposed))

  done()

  function expose(file) {
    var landmarks = file.data[landmarkId]

    if (landmarks) {
      xtend(exposed, landmarks)
    }
  }
}
function cliCompleter(set, done) {
  var exposed = {}

  set.valueOf().forEach(expose)
  set.valueOf().forEach(checkFactory(exposed))

  done()

  function expose(file) {
    var landmarks = file.data[landmarkId]

    if (landmarks) {
      xtend(exposed, landmarks)
    }
  }
}
Completer for the CLI (multiple files, and support to add more).