How to use

foldVoid

method

in

com.headius.invokebinder.Binder

/**
 * Pass all arguments to the given function and drop any result.
 *
 * @param function a function which will receive all arguments and have its
 *                 return value inserted into the call chain
 * @return a new SmartBinder with the fold applied
 */
public SmartBinder foldVoid(MethodHandle function) {
  return new SmartBinder(this, signature(), binder.foldVoid(function));
}

private MethodHandle nativeTryFinally(MethodHandle target, MethodHandle post) {
  MethodType targetType = target.type();
  boolean voidReturn = targetType.returnType() == Void.TYPE;
  MethodType finallyType = targetType.insertParameterTypes(0, Throwable.class);
  int dropCount = 1;
  if (!voidReturn) {
    finallyType = finallyType.insertParameterTypes(1, targetType.returnType());
    dropCount = 2;
  }
  MethodHandle wrapPost = Binder
      .from(finallyType)
      .drop(0, dropCount)
      .invoke(post);
  if (!voidReturn) {
    wrapPost = Binder.from(finallyType)
        .foldVoid(wrapPost)
        .permute(1)
        .identity();
  }
  try {
    return (MethodHandle) tryFinallyJava9.invokeExact(target, wrapPost);
  } catch (Throwable t) {
    throw new RuntimeException("Java 9 detected but MethodHandles.tryFinally missing", t);
  }
}

.foldVoid(traceCall)
.tryFinally(traceReturn)
.invoke(target);

.foldVoid(traceCall)
.tryFinally(traceReturn)
.invoke(target);