- postpone pruning / interface auto-detection to top task-level
only the task state knows for sure, that it requires its wrapped child to push to both ends
- perform connectivity validation only after pruning
only then, we the interfaces are completely determined
works if propagation direction can be derived from a generator or
connecting stage within the sequence
start-to-end propagation through whole serial container still fails
Establishing the interface connections, we face a chicken-egg-problem:
To establish a connection, a predecessors/successors pull interface is
assigned to the current's stage push interface.
However, propagating stages (in auto-detection mode) can only create
their pull interfaces if the corresponding, opposite-side push interface
is present already (because that's the mechanism to determine the supported
propagation directions).
Hence, we need to resolve this by performing two sweeps:
- initialization, assuming both propagation directions should be supported,
thus generating both pull interfaces, i.e. providing the egg
- stripping down the interfaces to the actual context
This context is provided by two stages pushing from both ends
into a (potentially long) sequence of propagating stages (tbd).
Contributions of this PR:
- PropagatingEitherWay: explicitly distinguish AUTO from BOTHWAYS interface
AUTO: auto-derive interface from provided push interfaces
BOTHWAYS: explicitly require both directions
- SerialContainer: (better, but not yet perfect) validation of connectivity
- ParallelContainer: determine interface from what children offer
- basic implementation for StagePrivate
- implementation for Stage calls this
- implementation for ContainerBase recursively calls this
- implementation for Task added
- store "failure" solutions to facilitate debugging
- Introspection assigns solution IDs as soon as they are created in a stage
Thus, solution IDs represent their creation order.
In contrast, the order of publishing (in StageStatistics) should
represent the cost order.
- Storing failures is disabled if Introspection is not available.
While ParallelContainers can directly promote their child solutions as
their own, a Wrapper needs to modify those solutions. Hence, Wrappers
should be derived directly from Container.
First from INTERFACE, second from PARENT.
INTERFACE initialization only makes sense for Propagating stages.
Connecting stages should ensure that interfaces define identical
properties which is not possible with boost::any.