@Override
public ARGPath getNextPathForInterpolation() {
ARGState current = sources.remove(0);
assert current.isTarget() : "current element is not a target";
ARGPathBuilder errorPathBuilder = ARGPath.reverseBuilder();
errorPathBuilder.add(
current, FluentIterable.from(AbstractStates.getOutgoingEdges(current)).first().orNull());
while (predecessorRelation.get(current) != null) {
ARGState parent = predecessorRelation.get(current);
if (stateHasFalseInterpolant(parent)) {
logger.log(
Level.FINEST,
"interpolant on path, namely for state ",
parent.getStateId(),
" is already false, so return empty path");
return EMPTY_PATH;
}
if (predecessorRelation.get(parent) != null) {
errorPathBuilder.add(parent, parent.getEdgeToChild(current));
}
current = parent;
}
return errorPathBuilder.build(current);
}
@Override
public ARGPath getNextPathForInterpolation() {
ARGPathBuilder errorPathBuilder = ARGPath.builder();
ARGState current = sources.pop();
if (!isValidInterpolationRoot(predecessorRelation.get(current))) {
logger.log(
Level.FINEST,
"interpolant of predecessor of ",
current.getStateId(),
" is already false, so return empty path");
return EMPTY_PATH;
}
// if the current state is not the root, it is a child of a branch , however, the path should
// not start with the
// child, but with the branching node (children are stored on the stack because this needs
// less book-keeping)
if (current != root) {
errorPathBuilder.add(
predecessorRelation.get(current),
predecessorRelation.get(current).getEdgeToChild(current));
}
while (successorRelation.get(current).iterator().hasNext()) {
Iterator<ARGState> children = successorRelation.get(current).iterator();
ARGState child = children.next();
errorPathBuilder.add(current, current.getEdgeToChild(child));
// push all other children of the current state, if any, onto the stack for later
// interpolations
int size = 1;
while (children.hasNext()) {
size++;
ARGState sibling = children.next();
logger.log(
Level.FINEST,
"\tpush new root ",
sibling.getStateId(),
" onto stack for parent ",
predecessorRelation.get(sibling).getStateId());
sources.push(sibling);
}
assert (size <= 2);
current = child;
}
return errorPathBuilder.build(current);
}