text: Changes
  =======
  
  (See :doc:`roadmap` for future plans.)
  
  
  Release History
  ---------------
  
  1.2.10
  ^^^^^^^^^^^^^^^^^^
  
  * Improved MidiFile.play to avoid time drift. (Implemented by John
    Belmonte, pull request #161.)
  
  * New ``repr()`` format. (Original implementation by John Belmonte,
    pull request #164.)
  
  * bugfix: MIDO_DEFAULT_INPUT was misspelled in mido-ports causing it
    to be show as 'not set' even though it was set. (Fix by Bernhard
    Wagner, pull request #192.)
  
  * Updated linke in docs to point to the new home github.com/mido/
    (Fixed by Joshua Mayers, pull request #177.)
  
  
  
  1.2.9 (2018-10-05)
  ^^^^^^^^^^^^^^^^^^
  
  * rewrote ``Parser`` class around a MIDI tokenizer. Should lead to
    slight speedup and much cleaner code.
  
  * bugfix: `data` attribute was missing for `UnknownMetaMessage`
    objects. This caused `AttributeError` when the messages were printed
    or saved to a file. Also, the documentation incorrectly listed the
    attribute as `_data` instead of `data`. (Reported by Groowy.)
  
  * bugfix: UnknownMetaMessage encoding was broken causing crashes when
    saving a file with unknown meta messages. (Reported by exeex, issue
    #159.)
  
  * bugfix: inputs and outputs were switched around when opening named
    ports with PortMidi backend. (Reproduced by Predrag Radovic, issue
    #108, fix by Juan Antonio Aldea, pull request #109.)
  
  * bugfix: time signature meta messages had wrong default value of
    2/4. The default value is now 4/4. (Fix by Sebastian Böck, pull
    request #104.)
  
  * bugfix: ``msg.copy()`` didn't handle generators for sysex
    data. ``msg.copy(data=(i for i in range(3)))`` would give
    ``data=()`` instead of ``data=(0,1,2)``.
  
    (The code should be refactored so this is handled by the same
    function everywhere, such as in ``__init__()``, in ``copy()`` and in
    ``parser.feed()``.)
  
  * bugfix: ``MultiPort._receive()`` ignored the ``block``
    parameter. (Fix by Tom Swirly, pull request #135.)
  
  * bugfix: sequencer number meta message was incorrectly limited to
    range 0..255 instead of 0..65335. (Reported by muranyia, issue
    #144.)
  
  * now using Tox for testing. (Implemented by Chris Apple, pull request
    #123.)
  
  * Travis integration up by Carl Thomé and Chris Apple.
  
  
  1.2.8 (2017-06-30)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: nonblocking receive was broken for RtMidi IO
    ports. (Reported by Chris Apple, issue #99.)
  
  * bugfix: ``IOPort.poll()`` would block if another thread was waiting
    for ``receive()``.  Fixed the problem by removing the lock, which
    was never needed in the first place as the embedded input port does
    its own locking.
  
  
  1.2.7 (2017-05-31)
  ^^^^^^^^^^^^^^^^^^
  * added max length when reading message from a MIDI file. This
    prevents Python from running out of memory when reading a corrupt
    file. Instead it will now raise an ``IOError`` with a descriptive
    error message. (Implemented by Curtis Hawthorne, pull request #95.)
  
  * removed dependency on ``python-rtmidi`` from tests. (Reported by
    Josue Ortega, issue #96.)
  
  
  1.2.6 (2017-05-04)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: Sending sysex with Pygame in Python 3 failed with
    ``"TypeError: array() argument 1 must be a unicode character, not
    byte"``.  (Reported by Harry Williamson.)
  
  * now handles ``sequence_number`` and ``midi_port`` messages with 0
    data bytes. These are incorrect but can occur in rare cases. See
    ``mido/midifiles/test_midifiles.py`` for more. (Reported by Gilthans
    (issue #42) and hyst329 (issue #93)).
  
  
  1.2.5 (2017-04-28)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: RtMidi backend ignored ``api`` argument. (Fix by Tom Feist,
    pull request #91.)
  
  
  1.2.4 (2017-03-19)
  ^^^^^^^^^^^^^^^^^^
  
  * fixed outdated python-rtmidi install instructions. (Reported by
    Christopher Arndt, issue #87.)
  
  
  1.2.3 (2017-03-14)
  ^^^^^^^^^^^^^^^^^^
  
  * typo and incorrect links in docs fixed by Michael (miketwo) (pull requests
    #84 and #85).
  
  
  1.2.2 (2017-03-14)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: sysex data was broken in string format encoding and decoding.
    The data was encoded with spaces ('data=(1, 2, 3)') instead of as one word
    ('data=(1,2,3)').
  
  * added some tests for string format.
  
  * bugfix: ``BaseOutput.send()`` raised string instead of ``ValueError``.
  
  
  1.2.1 (2017-03-10)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: IO port never received anything when used with RtMidi
    backend. (Reported by dagargo, issue #83.)
  
    This was caused by a very old bug introduced in 1.0.3. IOPort
    mistakenly called the inner method ``self.input._receive()`` instead
    of ``self.input.receive()``. This happens to work for ports that
    override ``_receive()`` but not for the new RtMidi backend which
    overrides ``receive()``. (The default implementation of
    ``_receive()`` just drops the message on the floor.)
  
  * bugfix: PortMidi backend was broken due to missing import
    (``ctypes.byref``). (Introduced in 1.2.0.)
  
  
  1.2.0 (2017-03-07)
  ^^^^^^^^^^^^^^^^^^^
  
  New implementation of messages and parser:
  
  * completely reimplemented messages. The code is now much simpler,
    clearer and easier to work with.
  
  * new contructors ``Message.from_bytes()``, ``Message.from_hex()``,
    ``Message.from_str()``.
  
  * new message attributes ``is_meta`` and ``is_realtime``.
  
  
  Frozen (immutable) messages:
  
  * added ``FrozenMessage`` and ``FrozenMetaMessage``. These are
    immutable versions of ``Message`` and ``MetaMessage`` that are
    hashable and thus can be used as dictionary keys. These are
    available in ``mido.frozen``. (Requested by Jasper Lyons, issue
    #36.)
  
  
  RtMidi is now the default backend:
  
  * switched default backend from PortMidi to RtMidi. RtMidi is easier
    to install on most systems and better in every way.
  
    If you want to stick to PortMidi you can either set the environment
    variable ``$MIDO_BACKEND=mido.backends.portmidi`` or call
    ``mido.set_backend('mido.backends.portmidi')`` in your program.
  
  * refactored the RtMidi backend to have a single ``Port`` class
    instead of inheriting from base ports. It was getting hard to keep
    track of it all. The code is now a lot easier to reason about.
  
  * you can now pass ``client_name`` when opening RtMidi ports:
    ``open_output('Test', client_name='My Client')``. When
    ``client_name`` is passed the port will automatically be a virtual
    port.
  
  * with ``LINUX_ALSA`` you can now omit client name and ALSA
    client/port number when opening ports, allowing you to do
    ``mido.open_output('TiMidity port 0')`` instead of
    ``mido.open_output('TiMidity:TiMidity port 0 128:0')``. (See RtMidi
    backend docs for more.)
  
  
  Changes to the port API:
  
  * ports now have ``is_input`` and ``is_output`` attributes.
  
  * new functions ``tick2second()`` and ``second2tick()``. (By Carl
    Thomé, pull request #71.)
  
  * added ``_locking`` attribute to ``BasePort``. You can set this to
    ``False`` in a subclass to do your own locking.
  
  * ``_receive()`` is now allowed to return a messages. This makes the
    API more consistent and makes it easier to implement thread safe
    ports.
  
  * ``pending()`` is gone. This had to be done to allow for the new
    ``_receive()`` behavior.
  
  * improved MIDI file documentation. (Written by Carl Thomé.)
  
  
  Other changes:
  
  * bugfix: if a port inherited from both ``BaseInput`` and
    ``BaseOutput`` this would cause ``BasePort.__init__()`` to be called
    twice, which means ``self._open()`` was also called twice. As a
    workaround ``BasePort.__init__()`` will check if ``self.closed``
    exists.
  
  * added ``mido.version_info``.
  
  * ``mido.set_backend()`` can now be called with ``load=True``.
  
  * added ``multi_send()``.
  
  * ``MIN_PITCHWHEEL``, ``MAX_PITCHWHEEL``, ``MIN_SONGPOS`` and
    ``MAX_SONGPOS`` are now available in the top level module (for
    example ``mido.MIN_PITCHWHEEL``).
  
  * added experimental new backend ``mido.backends.amidi``. This uses
    the ALSA ``amidi`` command to send and receive messages, which makes
    it very inefficient but possibly useful for sysex transfer.
  
  * added new backend ``mido.backends.rtmidi_python`` (previously
    available in the examples folder.) This uses the ``rtmidi-python``
    package instead of ``python-rtmidi``. For now it lacks some of
    features of the ``rtmidi`` backend, but can still be useful on
    systems where ``python-rtmidi`` is not available. (Requested by
    netchose, issue #55.)
  
  
  1.1.24 (2017-02-16)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: PortMidi backend was broken on macOS due to a typo. (Fix by
    Sylvain Le Groux, pull request #81.)
  
  
  1.1.23 (2017-01-31)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: ``read_syx_file()`` didn't handle '\n' in text format file
    causing it to crash. (Reported by Paul Forgey, issue #80.)
  
  
  1.1.22 (2017-01-27)
  ^^^^^^^^^^^^^^^^^^^
  
  * the bugfix in 1.1.20 broke blocking receive() for RtMidi. Reverting
    the changes. This will need some more investigation.
  
  
  1.1.21 (2017-01-26)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: MidiFile save was broken in 1.1.20 due to a missing import.
  
  
  1.1.20 (2017-01-26)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: close() would sometimes hang for RtMidi input ports. (The
    bug was introduced in 1.1.18 when the backend was rewritten to
    support true blocking.)
  
  * Numpy numbers can now be used for all message attributes. (Based on
    implementation by Henry Mao, pull request #78.)
  
    The code checks against numbers.Integral and numbers.Real (for the
    time attribute) so values can be any subclass of these.
  
  
  1.1.19 (2017-01-25)
  ^^^^^^^^^^^^^^^^^^^
  
  * Pygame backend can now receive sysex messages. (Fix by Box of Stops.)
  
  * bugfix: ``libportmidi.dylib`` was not found when using
    MacPorts. (Fix by yam655, issue #77.)
  
  * bugfix: ``SocketPort.__init()`` was not calling
    ``IOPort.__init__()`` which means it didn't get a
    ``self._lock``. (Fixed by K Lars Lohn, pull request #72. Also
    reported by John J. Foerch, issue #79.)
  
  * fixed typo in intro example (README and index.rst). Fix by Antonio
    Ospite (pull request #70), James McDermott (pull request #73) and
    Zdravko Bozakov (pull request #74).
  
  * fixed typo in virtual ports example (Zdravko Bozakov, pull request #75.)
  
  
  1.1.18 (2016-10-22)
  ^^^^^^^^^^^^^^^^^^^
  
  * ``time`` is included in message comparison. ``msg1 == msg2`` will
    now give the same result as ``str(msg1) == str(msg2)`` and
    ``repr(msg1)`` == ``repr(msg2)``.
  
    This means you can now compare tracks wihout any trickery, for
    example: ``mid1.tracks == mid2.tracks``.
  
    If you need to leave out time the easiest was is ``msg1.bytes() ==
    msg2.bytes()``.
  
    This may in rare cases break code.
  
  * bugfix: ``end_of_track`` messages in MIDI files were not handled correctly.
    (Reported by Colin Raffel, issue #62).
  
  * bugfix: ``merge_tracks()`` dropped messages after the first
    ``end_of_track`` message. The new implementation removes all
    ``end_of_track`` messages and adds one at the end, making sure to
    adjust the delta times of the remaining messages.
  
  * refactored MIDI file code.
  
  * ``mido-play`` now has a new option ``-m / --print-messages`` which
    prints messages as they are played back.
  
  * renamed ``parser._parsed_messages`` to
    ``parser.messages``. ``BaseInput`` and ``SocketPort`` use it so it
    should be public.
  
  * ``Parser()`` now takes an option argument ``data`` which is passed
    to ``feed()``.
  
  
  1.1.17 (2016-10-06)
  ^^^^^^^^^^^^^^^^^^^
  
  * RtMidi now supports true blocking ``receive()`` in Python 3. This
    should result in better performance and lower latency. (Thanks to
    Adam Roberts for helping research queue behavior. See issue #49 for
    more.)
  
  * bugfix: ``MidiTrack.copy()`` (Python 3 only) returned ``list``.
  
  * fixed example ``queue_port.py`` which broke when locks where added.
  
  
  1.1.16 (2016-09-27)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: ``MidiTrack`` crashed instead of returning a message on
    ``track[index]``. Fix by Colin Raffel (pull request #61).
  
  * added ``__add__()`` and ``__mul__()`` to ``MidiTrack`` so ``+`` and
    ``*`` will return tracks instead of lists.
  
  * added ``poll()`` method to input ports as a shortcut for
    ``receive(block=False)``.
  
  * added example ``rtmidi_python_backend.py``, a backend for the
    rtmidi-python package (which is different from the python-rtmidi
    backend that Mido currently uses.) This may at some point be added
    to the package but for now it's in the examples folder. (Requested
    by netchose, issue #55.)
  
  * removed custom ``_import_module()``. Its only function was to make
    import errors more informative by showing the full module path, such
    as ``ImportError: mido.backends.rtmidi`` instead of just ``ImportError:
    rtmidi``. Unfortunately it ended up masking import errors in the
    backend module, causing confusion.
  
    It turns ``importlib.import_module()`` can be called with the full
    path, and on Python 3 it will also display the full path in the
    ``ImportError`` message.
  
  
  1.1.15 (2016-08-24)
  ^^^^^^^^^^^^^^^^^^^
  
  * Sending and receiving messages is now thread safe. (Initial
    implementation by Adam Roberts.)
  
  * Bugfix: ``PortServer`` called ``__init__`` from the wrong
    class. (Fix by Nathan Hurst.)
  
  * Changes to ``MidiTrack``:
  
    * ``MidiTrack()`` now takes a as a parameter an iterable of
      messages. Examples:
  
      .. code-block:: python
  
          MidiTrack(messages)
          MidiTrack(port.iter_pending())
          MidiTrack(msg for msg in some_generator)
  
    * Slicing a ``MidiTrack`` returns a ``MidiTrack``. (It used to
      return a ``list``.) Example:
  
      .. code-block:: python
  
          track[1:10]
  
  * Added the ability to use file objects as well as filenames when reading,
    writing and saving MIDI files. This allows you to create a MIDI file
    dynamically, possibly *not* using mido, save it to an io.BytesIO, and
    then play that in-memory file, without having to create an intermediate
    external file. Of course the memory file (and/or the MidiFile) can still
    be saved to an external file.
    (Implemented by Brian O'Neill.)
  
  * PortMidi backend now uses pm.lib.Pm_GetHostErrorText() to get host
    error messages instead of just the generic "PortMidi: \`Host error\'".
    (Implemented by Tom Manderson.)
  
  Thanks to Richard Vogl and Tim Cook for reporting errors in the docs.
  
  
  1.1.14 (2015-06-09)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: merge_tracks() concatenated the tracks instead of merging
    them.  This caused tracks to be played back one by one. (Issue #28,
    reported by Charles Gillingham.)
  
  * added support for running status when writing MIDI files.
    (Implemented by John Benediktsson.)
  
  * rewrote the callback system in response to issues #23 and #25.
  
  * there was no way to set a callback function if the port was opened
    without one. (Issue#25, reported by Nils Werner.)
  
    Callbacks can now be set and cleared at any time by either passing
    one to ``open_input()`` or updating the ``callback`` attribute.
  
    This causes some slight changes to the behavior of the port when
    using callbacks. Previously if you opened the port with a callback
    and then set ``port.callback = None`` the callback thread would keep
    running but drop any incoming messages. If you do the same now the
    callback thread will stop and the port will return normal
    non-callback behavior. If you want the callback thread to drop
    messages you can set ``port.callback = lambda message: None``.
  
    Also, ``receive()`` no longer checks ``self.callback``. This was
    inconsistent as it was the only method to do so. It also allows
    ports that don't support callbacks to omit the ``callback``
    attribute.
  
  * bugfix: closing a port would sometimes cause a segfault when using
    callbacks. (Issue #24, reported by Francesco Ceruti.)
  
  * bugfix: Pygame ports were broken due to a faulty check for ``virtual=True``.
  
  * now raises ``ValueError`` instead of ``IOError`` if you pass
    ``virtual`` or ``callback`` while opening a port and the backend
    doesn't support them. (An unsupported argument is not an IO error.)
  
  * fixed some errors in backend documentation. (Pull request #23 by
    velolala.)
  
  * ``MultiPort`` now has a ``yield_port`` argument just like
    ``multi_receive()``.
  
  
  1.1.13 (2015-02-07)
  ^^^^^^^^^^^^^^^^^^^
  
  * the PortMidi backend will now return refresh the port list when you
    ask for port names are open a new port, which means you will see
    devices that you plug in after loading the backend. (Due to
    limitations in PortMidi the list will only be refreshed if there are
    no open ports.)
  
  * bugfix: ``tempo2bpm()`` was broken and returned the wrong value for
    anything but 500000 microseconds per beat (120 BPM). (Reported and
    fixed by Jorge Herrera, issue #21)
  
  * bugfix: ``merge_tracks()`` didn't work with empty list of tracks.
  
  * added proper keyword arguments and doc strings to open functions.
  
  
  1.1.12 (2014-12-02)
  ^^^^^^^^^^^^^^^^^^^
  
  * raises IOError if you try to open a virtual port with PortMidi or
    Pygame. (They are not supported by these backends.)
  
  * added ``merge_tracks()``.
  
  * removed  undocumented method ``MidiFile.get_messages()``.
    (Replaced by ``merge_tracks(mid.tracks)``.)
  
  * bugfix: ``receive()`` checked ``self.callback`` which didn't exist
    for all ports, causing an ``AttributeError``.
  
  
  1.1.11 (2014-10-15)
  ^^^^^^^^^^^^^^^^^^^
  
  * added ``bpm2tempo()`` and ``tempo2bpm()``.
  
  * fixed error in documentation (patch by Michael Silver).
  
  * added notes about channel numbers to documentation (reported by
    ludwig404 / leonh, issue #18).
  
  
  1.1.10 (2014-10-09)
  ^^^^^^^^^^^^^^^^^^^
  
  * bugfix: MidiFile.length was computer incorrectly.
  
  * bugfix: tempo changes caused timing problems in MIDI file playback.
    (Reported by Michelle Thompson.)
  
  * mido-ports now prints port names in single ticks.
  
  * MidiFile.__iter__() now yields end_of_track. This means playback
    will end there instead of at the preceding message.
  
  
  1.1.9 (2014-10-06)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: _compute_tick_time() was not renamed to
    _compute_seconds_per_tick() everywhere.
  
  * bugfix: sleep time in play() was sometimes negative.
  
  
  1.1.8 (2014-09-29)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: timing in MIDI playback was broken from 1.1.7 on.  Current
    time was subtracted before time stamps were converted from ticks to
    seconds, leading to absurdly large delta times. (Reported by Michelle
    Thompson.)
  
  * bugfix: ``read_syx_file()`` didn't handle empty file.
  
  
  1.1.7 (2014-08-12)
  ^^^^^^^^^^^^^^^^^^
  
  * some classes and functions have been moved to more accessible locations::
  
      from mido import MidiFile, MidiTrack, MetaMessage
      from mido.midifiles import MetaSpec, add_meta_spec
  
  * you can now iterate over a MIDI file. This will generate all MIDI
    messages in playback order. The ``time`` attribute of each message
    is the number of seconds since the last message or the start of the
    file. (Based on suggestion by trushkin in issue #16.)
  
  * added get_sleep_time() to complement set_sleep_time().
  
  * the Backend object no longer looks for the backend module exists on
    startup, but will instead just import the module when you call one
    of the ``open_*()`` or ``get_*()`` functions. This test didn't work
    when the library was packaged in a zip file or executable.
  
    This means that Mido can now be installed as Python egg and frozen
    with tools like PyInstaller and py2exe. See "Freezing Mido Programs"
    for more on this.
  
    (Issue #17 reported by edauenhauer and issue #14 reported by
    netchose.)
  
  * switched to pytest for unit tests.
  
  
  1.1.6 (2014-06-21)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: package didn't work with easy_install.
    (Issue #14, reported by netchose.)
  
  * bugfix: 100% memory consumption when calling blocking receive()
    on a PortMidi input. (Issue #15, reported by Francesco Ceruti.)
  
  * added wheel support: http://pythonwheels.com/
  
  
  1.1.5 (2014-04-18)
  ^^^^^^^^^^^^^^^^^^
  
  * removed the 'mode' attribute from key_signature messages. Minor keys
    now have an 'm' appended, for example 'Cm'.
  
  * bugfix: sysex was broken in MIDI files.
  
  * bugfix: didn't handle MIDI files without track headers.
  
  * bugfix: MIDI files didn't handle channel prefix > 15
  
  * bugfix: MIDI files didn't handle SMPTE offset with frames > 29
  
  
  1.1.4 (2014-10-04)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: files with key signatures Cb, Db and Gb failed due to faulty
    error handling.
  
  * bugfix: when reading some MIDI files Mido crashed with the message
    "ValueError: attribute must be in range 0..255". The reason was that
    Meta messages set running status, which caused the next statusless
    message to be falsely interpreted as a meta message. (Reported by
    Domino Marama).
  
  * fixed a typo in MidiFile._read_track(). Sysex continuation should
    work now.
  
  * rewrote tests to make them more readable.
  
  
  1.1.3 (2013-10-14)
  ^^^^^^^^^^^^^^^^^^
  
  * messages are now copied on send. This allows the sender to modify the
    message and send it to another port while the two ports receive their
    own personal copies that they can modify without any side effects.
  
  
  1.1.2 (2013-10-05)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: non-ASCII character caused trouble with installation when LC_ALL=C.
    (Reported by Gene De Lisa)
  
  * bugfix: used old exception handling syntax in rtmidi backend which
    broke in 3.3
  
  * fixed broken link in
  
  
  1.1.1 (2013-10-04)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: mido.backends package was not included in distribution.
  
  
  1.1.0 (2013-10-01)
  ^^^^^^^^^^^^^^^^^^
  
  * added support for selectable backends (with MIDO_BACKEND) and
    included python-rtmidi and pygame backends in the official library
    (as mido.backend.rtmidi and mido.backend.pygame).
  
  * added full support for MIDI files (read, write playback)
  
  * added MIDI over TCP/IP (socket ports)
  
  * added utility programs mido-play, mido-ports, mido-serve and mido-forward.
  
  * added support for SMPTE time code quarter frames.
  
  * port constructors and ``open_*()`` functions can now take keyword
    arguments.
  
  * output ports now have reset() and panic() methods.
  
  * new environment variables MIDO_DEFAULT_INPUT, MIDO_DEFAULT_OUTPUT
    and MIDO_DEFAULT_IOPORT. If these are set, the open_*() functions
    will use them instead of the backend's default ports.
  
  * added new meta ports MultiPort and EchoPort.
  
  * added new examples and updated the old ones.
  
  * format_as_string() now takes an include_time argument (defaults to True)
    so you can leave out the time attribute.
  
  * sleep time inside sockets can now be changed.
  
  * Message() no longer accepts a status byte as its first argument. (This was
    only meant to be used internally.)
  
  * added callbacks for input ports (PortMidi and python-rtmidi)
  
  * PortMidi and pygame input ports now actually block on the device
    instead of polling and waiting.
  
  * removed commas from repr() format of Message and MetaMessage to make
    them more consistent with other classes.
  
  
  1.0.4 (2013-08-15)
  ^^^^^^^^^^^^^^^^^^
  
  * rewrote parser
  
  
  1.0.3 (2013-07-12)
  ^^^^^^^^^^^^^^^^^^
  
  * bugfix: __exit__() didn't close port.
  
  * changed repr format of message to start with "message".
  
  * removed support for undefined messages. (0xf4, 0xf5, 0xf7, 0xf9 and 0xfd.)
  
  * default value of velocity is now 64 (0x40).
    (This is the recommended default for devices that don't support velocity.)
  
  
  1.0.2 (2013-07-31)
  ^^^^^^^^^^^^^^^^^^
  
  * fixed some errors in the documentation.
  
  
  1.0.1 (2013-07-31)
  ^^^^^^^^^^^^^^^^^^
  
  * multi_receive() and multi_iter_pending() had wrong implementation.
    They were supposed to yield only messages by default.
  
  
  1.0.0 (2013-07-20)
  ^^^^^^^^^^^^^^^^^^
  
  Initial release.
  
  Basic functionality: messages, ports and parser.
  