Package jetbrains.mps.generator.impl

Class TransitionTrace

java.lang.Object

jetbrains.mps.generator.impl.TransitionTrace

public final class TransitionTrace
extends Object

Ensures we trace origin of node in a transient model, whether it's original input model or one of previous checkpoint steps. Keeps traces for each node in the model during transformation phase, and once the phase is over, this trace is used to populate label mappings information that will persist. Once mappings are ready, the trace is of no use and can be disposed (unless we decide to use it as a replacement for TracingUtil and navigation from transient models back to original one. ModelTransitions is the source of TransitionTrace, and keeps track of CP-CP transitions (similar to ModelCheckpoints->CheckpointState relation, just for the active transformation). TransitionTrace knows last checkpoint (if any), and doesn't know next one. Now it's GenPlanActiveStep that keeps track of the plan and actual position in there. Perhaps, that's not the most elegant approach. If a model M passes through a sequence of M1 -> CP1 -> M2 -> M3 -> CP2 -> M4, transition traces for the model are: TT(null), TT(CP1), TT(CP2). FIXME inputNode may not necessarily come from the input model, it might be arbitrary non-transient (or even perhaps checkpoint?!) model, thus saving nodeId is not sufficient. OTOH, don't want to save SNodeReference as it's superficial in most regular cases

Method Summary

Modifier and Type	Method	Description
void	deriveOrigin(SNode inputNode, SNode outputNode)	Output node derives its origin from the given input node.
void	deriveOrigin(SNode inputNode, TreeIterator<SNode> outputNodes)	Initialize origin for a tree of nodes.
ModelTransitions	getModelTrace()
SNodeId	getOrigin(SNode node)
boolean	hasOrigin(SNode node)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getModelTrace

public ModelTransitions getModelTrace()

Returns:

never null

hasOrigin

public boolean hasOrigin(@NotNull
                         SNode node)

getOrigin

@Nullable
public SNodeId getOrigin(@NotNull
                         SNode node)

deriveOrigin

public void deriveOrigin(@NotNull
                         SNode inputNode,
                         @NotNull
                         SNode outputNode)

Output node derives its origin from the given input node. If output node already got an origin, it's preserved. If input node has no trace, output node gets none as well. No child of output node is processed.

deriveOrigin

public void deriveOrigin(@NotNull
                         SNode inputNode,
                         @NotNull
                         TreeIterator<SNode> outputNodes)

Initialize origin for a tree of nodes. Output nodes get origin unless they already got one, in this case complete subtree is ignored (it's assumed the sub-tree already got origin assigned, no reason to override it)