cd598c28ae
At the moment `Ap` state contains vector of generations, although the ap instruction itself allow to specify only one stream. It was done to support several streams in a result position in a future. But the current realization allows to handle empty vector that was implemented to support states for scalars and it turned out (for more info see #326) that states for scalars aren't actually needed. Closes #355.
AIR trace handler
This crate contains implementation of the CRDT-based merging data algorithm. It exposes the TraceHandler struct that based on the visitor pattern and has public methods that should be called in certain places of AIR instructions execution. Internally TraceHandler contains several FSM and each of such public methods does state transitioning of one or more these FSMs. Below are state transition sequences for all instructions that caller must follow.
Ap instruction
Expected sequence of TraceHandler calls for the ap instruction:
meet_ap_start
-> meet_ap_end
Call instruction
Expected sequence of TraceHandler calls for the call instruction:
meet_call_start
-> meet_call_end
Par instruction
Expected sequence of TraceHandler calls for the par instruction:
meet_par_start
-> meet_par_subgraph_end(..., SubgraphType::Left)
-> meet_par_subgraph_end(..., SubgraphType::Right)
Fold instruction
Expected sequence of TraceHandler calls for the fold instruction:
meet_fold_start.1 ->
meet_generation_start.N ->
meet_next.M ->
meet_prev.M ->
meet_generation_end.N ->
meet_fold_end.1
where .T means that this function should be called exactly T times.