TC 0.7.0 introduces a new `TaskData` type that maps to Taskwarrior's
`Task` type more cleanly. It also introduces the idea of gathering lists
of operations and "committing" them to a replica.
A consequence of this change is that TaskChampion no longer
automatically maintains dependency information, so Taskwarrior must do
so, with its `TDB2::dependency_sync` method. This method does a very
similar thing to what TaskChampion had been doing, so this is a shift of
responsibility but not a major performance difference.
Cxx is .. not great. It is missing a lot of useful things that make a
general-purpose bridge impractical:
- no support for trait objects
- no support for `Option<T>` (https://github.com/dtolnay/cxx/issues/87)
- no support for `Vec<Box<..>>`
As a result, some creativity is required in writing the bridge, for
example returning a `Vec<OptionTaskData>` from `all_task_data` to allow
individual `TaskData` values to be "taken" from the vector.
That said, Cxx is the current state-of-the-art, and does a good job of
ensuring memory safety, at the cost of some slightly awkward APIs.
Subsequent work can remove the "TDB2" layer and allow commands and other
parts of Taskwarrior to interface directly with the `Replica`.
getDOM takes an &Task that may be a reference to a dummy, or may be a
real task. The is_empty method replaces `task.data.size() == 0` as a
way to distinguish the two.
This also drops support for the transitional `json.depends.array`
configuration value, which has not been necessary since ~2016.
As with tags, dependencies are stored in both a "combined",
comma-separated format (for compatibility) and in an
attribute-per-dependency format (for the future).
Each tag is stored as `tag_<tagname>: x`. The `x` is required because
empty attributes are treated as nonexistent.
For compatibility, the `tags` attribute is updated in sync with the
per-tag attributes. This compatibility support may be dropped in later
versions.
Note that synchronization _updates_ use JSON format, which does not
change with this patch, and thus no compatibility issues exist. The
synchronization _initialization_, however, uses FF4, meaning that a
sync server initialized from a version of `task` with this patch will
contain `tag_<tagname>` attributes, which will look like orphaned UDAs
to older versions. However, as updates to tasks are synchronized via
the sync server, the updates will not contain these attributes and they
will show as "deleted" in the `task info` display on the older version.
Aside from the noise in the `task info` output, this is harmless.
During construction of a feedback string for a dependency change,
a list of IDs of the dependencies was used. However, if the tasks
being referred to are already deleted / completed, their respective
IDs are all 0s.
Use shortened UUIDs in such case.
- Make the Task object's interface more explicit by removing the
std::map inheritance.
- Using this more explicit interface, remove unneeded ctors in order to
allow the compiler to "Do The Right Thing"(tm).
This leads to a performance improvement of 12% in the "add"
performance test, and 7% for "import".
- Task::modify now considers the 'g' at the end of a substitution to be a
string of characters, which may contain 'g'. No other flags are currently
supported.
