private static CompoundInitialState createState(InferenceSession topLevelSession) {
final PsiSubstitutor topInferenceSubstitutor =
replaceVariables(topLevelSession.getInferenceVariables());
final Map<PsiElement, InitialInferenceState> nestedStates =
new LinkedHashMap<PsiElement, InitialInferenceState>();
final InferenceSessionContainer copy =
new InferenceSessionContainer() {
@Override
public PsiSubstitutor findNestedSubstitutor(
PsiElement arg, @Nullable PsiSubstitutor defaultSession) {
// for the case foo(bar(a -> m())): top level inference won't touch lambda "a -> m()"
// for the case foo(a -> bar(b -> m())): top level inference would go till nested lambda
// "b -> m()" and the state from top level could be found here by "bar(b -> m())"
// but proceeding with additional constraints from saved point would produce new
// expression constraints with different inference variables (could be found in
// myNestedSessions)
// which won't be found in the system if we won't reject stored sessions in such cases
final PsiSubstitutor substitutor = super.findNestedSubstitutor(arg, null);
if (substitutor != null) {
return substitutor;
}
final InitialInferenceState state =
nestedStates.get(PsiTreeUtil.getParentOfType(arg, PsiCall.class));
if (state != null) {
return state.getInferenceSubstitutor();
}
return super.findNestedSubstitutor(arg, defaultSession);
}
};
final Map<PsiElement, InferenceSession> nestedSessions =
topLevelSession.getInferenceSessionContainer().myNestedSessions;
for (Map.Entry<PsiElement, InferenceSession> entry : nestedSessions.entrySet()) {
nestedStates.put(
entry.getKey(),
entry
.getValue()
.createInitialState(
copy, topLevelSession.getInferenceVariables(), topInferenceSubstitutor));
}
PsiSubstitutor substitutor = PsiSubstitutor.EMPTY;
for (InferenceVariable variable : topLevelSession.getInferenceVariables()) {
final PsiType instantiation = variable.getInstantiation();
if (instantiation != PsiType.NULL) {
final PsiClass psiClass =
PsiUtil.resolveClassInClassTypeOnly(topInferenceSubstitutor.substitute(variable));
if (psiClass instanceof InferenceVariable) {
substitutor = substitutor.put((PsiTypeParameter) psiClass, instantiation);
}
}
}
return new CompoundInitialState(substitutor, nestedStates);
}
void registerNestedSession(
InferenceSession session, PsiType returnType, PsiExpression returnExpression) {
final PsiSubstitutor callSession =
findNestedSubstitutor(((PsiCallExpression) returnExpression).getArgumentList(), null);
if (callSession == null) {
final InferenceSession inferenceSession =
ExpressionCompatibilityConstraint.reduceExpressionCompatibilityConstraint(
session, returnExpression, returnType);
if (inferenceSession != null && inferenceSession != session) {
registerNestedSession(inferenceSession);
session.propagateVariables(
inferenceSession.getInferenceVariables(),
inferenceSession.getRestoreNameSubstitution());
}
}
}