@Nullable
public static PsiType getExpectedClosureReturnType(GrClosableBlock closure) {
final Set<PsiType> expectedTypes = getDefaultExpectedTypes(closure);
List<PsiType> expectedReturnTypes = new ArrayList<PsiType>();
for (PsiType expectedType : expectedTypes) {
if (!(expectedType instanceof PsiClassType)) return null;
final PsiClassType.ClassResolveResult resolveResult =
((PsiClassType) expectedType).resolveGenerics();
final PsiClass resolved = resolveResult.getElement();
if (resolved == null
|| !(GroovyCommonClassNames.GROOVY_LANG_CLOSURE.equals(resolved.getQualifiedName())))
return null;
final PsiTypeParameter[] typeParameters = resolved.getTypeParameters();
if (typeParameters.length != 1) return null;
final PsiTypeParameter expected = typeParameters[0];
final PsiType expectedReturnType = resolveResult.getSubstitutor().substitute(expected);
if (expectedReturnType == PsiType.VOID || expectedReturnType == null) return null;
expectedReturnTypes.add(expectedReturnType);
}
return TypesUtil.getLeastUpperBoundNullable(expectedReturnTypes, closure.getManager());
}
@Override
public void visitSwitchStatement(GrSwitchStatement switchStatement) {
final GrCaseSection[] sections = switchStatement.getCaseSections();
List<PsiType> types = new ArrayList<PsiType>(sections.length);
for (GrCaseSection section : sections) {
final GrExpression value = section.getCaseLabel().getValue();
final PsiType type = value != null ? value.getType() : null;
if (type != null) types.add(type);
}
final PsiType upperBoundNullable =
TypesUtil.getLeastUpperBoundNullable(types, switchStatement.getManager());
if (upperBoundNullable == null) return;
myResult = new TypeConstraint[] {SubtypeConstraint.create(upperBoundNullable)};
}
@Override
public PsiType fun(GrAssignmentExpressionImpl assignment) {
final GroovyResolveResult[] results = assignment.multiResolve(false);
if (results.length == 0) {
final GrExpression rValue = assignment.getRValue();
return rValue == null ? null : rValue.getType();
}
PsiType returnType = null;
final PsiManager manager = assignment.getManager();
for (GroovyResolveResult result : results) {
final PsiType substituted =
ResolveUtil.extractReturnTypeFromCandidate(result, assignment);
returnType = TypesUtil.getLeastUpperBoundNullable(returnType, substituted, manager);
}
return returnType;
}