0.4.2

Released: 2018-06-07

Bugfixes

Variable-length integer fields now set their size attribute if const is
defined. Not doing so was apparently a deliberate decision (there was a unit test for it), which I no longer
understand.

Other Changes

• Union now throws a ConfigurationError if it gets a Field class
  instead of an instance of a Field class. This would otherwise result in
  hard to debug TypeErrors being thrown when trying to load or dump.
• Trying to use a computes decorator on a const field will trigger a
  ConfigurationError.
• Bytes no longer crashes with an UndefinedSizeError if it isn't given a
  size. I'm not sure why I ever thought that Bytes should only be a fixed
  length.

0.4.1

Released: 2018-05-13

Bugfixes

• Struct size couldn't be calculated if the struct contained computed fields or
  had to use the default value for any field.
• Setting the value of a computed or const field would persist until that field
  was deleted. Trying to modify a computed or const field will now trigger a
  ImmutableFieldError.
• Accessing a field as an attribute no longer sets the field to its default
  value if the field hasn't been assigned yet. This made sense before computed
  fields were added, since ostensibly changing one field wouldn't affect any
  others.
• Values assigned to a struct using dictionary notation were not validated.
• len() now throws a MissingRequiredValueError exception if the struct
  size couldn't be computed. UndefinedSizeError is a configuration error and
  in retrospect made no sense to throw there.
• A better error message is shown when accessing a Struct using a field name
  that doesn't exist.
• Attempting to get the value of a field that hasn't been set yet via dictionary
  access used to throw a KeyError even if it was a computed field. Now it
  throws the expected MissingRequiredValueError.

Other Changes

• Dictionary methods on Struct like get, setdefault, etc. are
  deprecated and should not be used anymore. They will be removed in 0.5.0.
• Validator decorators now detect when they're being misused (i.e. called as
  @validator instead of @validator() and throw a helpful exception.
• Bump tested CPython versions to the latest release, i.e. 3.4.7 -> 3.4.8, etc.
• Bump PyPy3.5 5.10 to v6.0

0.4.0

Released: 2018-04-21

Bugfixes

• Removed unused __computed_fields__ property from Struct classes. It was
  accidentally left in.
• Fixed WAV file generation in the examples. It was writing the frequency of the
  wave to the file, not the amplitude.
• Miscellaneous tweaks and typo corrections in documentation.

Features

Added support for adding validators on fields, both as methods in their Struct
and passed in to the constructor. You can also have validator methods that
validate the entire Struct just after loading or just before dumping.

Breaking Changes

• Dropped support for Python 3.3, which has been deprecated. Please upgrade to a
  newer version of Python.
• VariableSizedFieldError was deprecated in 0.3.1. It has been removed and
  completely replaced by UndefinedSizeError.

Other Changes

• Start testing on Python 3.7.
• Assigning directly to the __values__ dict in a Struct is deprecated,
  as it circumvents validators. __values__ will be removed in a future
  release.

0.3.1

Released: 2018-03-28

Bugfixes

• Fixed bug where Bytes wasn't checking how many bytes it was writing when
  dumping.
• Fixed bug where Field.size was incorrectly computed for fields where
  len(const) wasn't equivalent to the field size, e.g. for String fields
  using a UTF-16 encoding.

Other Changes

• VariableSizedFieldError has been deprecated, and will be replaced by
  UndefinedSizeError. This is because the exception name and error message
  was misleadingly narrow in scope.
• Removed undocumented loaded_fields and all_fields arguments from the
  loading and dumping methods in Struct. They were left in by mistake and
  never used.

0.3.0

Released: 2018-03-23

Bugfixes

• Fixed field redefinition detection. Subclassing wasn't supported in earlier
  versions but the code was still there.

Features

1. Array can now take another Field or a string naming a Field as its
   count argument. This lets you avoid having to write a halting function:

    # As of 0.3.0:
    class MyStruct(Struct):
        n_numbers = UInt16()
        numbers = Array(UInt16(), count=n_numbers)

    # For earlier versions:

    def halt_n_numbers(seq, stream, values, context, loaded_fields):
        return len(values) >= loaded_fields['n_numbers']

    class MyStruct(Struct):
        n_numbers = UInt16()
        numbers = Array(UInt16(), halt_check=halt_n_numbers)

2. The new computes decorator gives you the ability to use a function to
   dynamically compute the value of a field when serializing, instead of passing
   it in yourself.

3. New field type Union allows you to emulate C's union storage class
   using fields, structs, or any combination of the two.

4. Added struct and obj keyword arguments to ConfigurationError to
   give more flexibility in what errors it and its subclasses can be used for.

Breaking Changes

None.

Documentation

• Changed development stage from alpha stage to beta.
• Expanded documentation of existing code, fixed inter-module references.

0.2.1

Released: 2018-03-18

Bugfixes

1. Fixed argument names in overridden methods of some fields differing from their
   superclass' signature. Affects Integer, String, StringZ and
   VariableLengthInteger.
2. Fixed to_dict() method of Struct so that it recurses and converts all
   nested fields and arrays into Python dicts as well. This means that the output
   of Struct.to_dict() is JSON-serializable if all fields are defined.
3. Changed BytesIO in documentation to BufferedIOBase since FileIO is
   also a legitimate input type.
4. Array halt functions can now reference the fields that have already been
   deserialized. This was supposed to be included in 0.1.0 but somehow was
   overlooked.

Breaking Changes

• The fix for bug 2:

  • dict(struct) and struct.to_dict() no longer give identical results.
  • For nested structures, struct.to_dict() will return dictionaries where
    the old behavior would return instances of those Struct objects. This
    only matters if your code relied on nested structs being Struct objects.

• The fix for bug 4 added additional a positional argument to _do_load,
  _do_dump, and the halt functions. This will break subclasses that define
  these functions, but the fix is minimal:

  • Add loaded_fields as the last argument to your halt functions as well as
    any overridden _do_load methods in custom fields.
  • Add all_fields as the last argument to _do_dump methods in custom
    fields.

Documentation

• Added WAV file example and unit tests.
• Changed "end to end tests" file into a BMP file example since it was only using
  the BMP format anyway.
• Added comprehensive tutorial on basics with a bit of intermediate stuff.

Version 0.2.0

Released: 2018-03-04

Bugfixes

• StringZ can now load strings in character encodings that use more than one
  byte to represent null, e.g. UTF-16.
• Fixed some typos in documentation.

Features

• String and its subclasses now take a pad_byte argument that pads strings
  with that byte if they're too short after encoding. For example:

>>> String(size=4, pad_byte=b' ').dumps('a')
b'a   '

Version 0.1.0

Initial release.