This introduces the DOM, the DiffX Object Model, which is a hierarchical
representation of DiffX files. It can be used to assemble a DiffX file
section-by-section, or to load in a DiffX file and process or manipulate
it.
There's an object for each type of section, organized into a tree. These
are divided into container and content sections, just as in the
specification.
To ease use, consumers really only have to deal with the container
sections (DiffX, DiffXChangeSection, and DiffXFileSection). The
content and options for each child content section is accessible via
forwarding attributes. For example, a DiffXChangeSection's preamble
text can be accessed directly through a preamble attribute, and the
preamble encoding can be accessed through preamble_encoding.
All attributes are type-safe, ensuring there are no problems when
writing a DiffX file. The classes are also limited in what attributes
can be set by defining __slots__, which helps to avoid accidentally
setting the wrong attribute name.
These objects manage data storage. All reading/writing is still done via
the underlying stream reader/writer, with specializations to convert
to-and-from the DOM.
It's expected that most users of the pydiffx module will use the DOM
implementaton, as it provides the easiest way of working with DiffX.
Future updates are planned to automatically calculate insert/line/file
statistics for metadata and to extract information from vendor-specific
Unified Diff variants.
