BP for acyclic graph: multiple destinations. #108
Description
What is the problem you would like to solve? Please describe.
When running BP on acyclic graph, we might want to infer more than one variable. This currently requires multiple calls to BPState.bp_acyclic , which will be non-optimal (in computation or memory usage).
Describe the solution you'd like
Give multiple dest variables to BP acyclic.
Implementation details
An efficient implementation is not trivial, as it requires finding a good order to run the propagation (a given node might have to be propagated more than once).
Alternatives
Not do it, or do it only in the case of a single dest per connected component in the graph (trivial and eases API, but not more powerful than what can already done with a single dest and a loop).