@spec transform(binary(), binary(), :atom) :: [binary()] | {:error, :file.posix()}

Transform a downloaded raw JSON page into a list of tab-delimited track data.

example

Example

  # transform a page of scrobbles from the file archive
  LastfmArchive.Transform.transform("a_lastfm_user", "2007/200_1.gz")

A row of tab-delimited track currently contains (if any):

• id auto-generated by the system to uniquely identify a scrobble
• name the track name
• scrobble_date Unix timestamp of the scrobble date
• scrobble_date_iso scrobble date in ISO 8601 datetime format
• mbid MusicBrainz identifier for the track
• url web address of the track on Last.fm
• artist
• artist_mbid MusicBrainz identifier for the artist
• artist_url web address of the artist on Last.fm
• album
• album_mbid MusicBrainz identifier for the album