How to use

cast

method

in

com.headius.invokebinder.Binder

/**
 * Cast the incoming arguments to the types in the given signature. The
 * argument count must match, but the names in the target signature are
 * ignored.
 *
 * @param target the Signature to which arguments should be cast
 * @return a new SmartBinder with the cast applied
 */
public SmartBinder cast(Signature target) {
  return new SmartBinder(target, binder.cast(target.type()));
}

public static CallSite fixnum(Lookup lookup, String name, MethodType type, long value) {
  MutableCallSite site = new MutableCallSite(type);
  MethodHandle handle = Binder
      .from(IRubyObject.class, ThreadContext.class)
      .insert(0, site, value)
      .cast(IRubyObject.class, MutableCallSite.class, long.class, ThreadContext.class)
      .invokeStaticQuiet(MethodHandles.lookup(), Bootstrap.class, "fixnum");
  site.setTarget(handle);
  return site;
}

public static CallSite flote(Lookup lookup, String name, MethodType type, double value) {
  MutableCallSite site = new MutableCallSite(type);
  MethodHandle handle = Binder
      .from(IRubyObject.class, ThreadContext.class)
      .insert(0, site, value)
      .cast(IRubyObject.class, MutableCallSite.class, double.class, ThreadContext.class)
      .invokeStaticQuiet(MethodHandles.lookup(), Bootstrap.class, "flote");
  site.setTarget(handle);
  return site;
}

public static CallSite fixnum(Lookup lookup, String name, MethodType type, long value) {
  MutableCallSite site = new MutableCallSite(type);
  MethodHandle handle = Binder
      .from(IRubyObject.class, ThreadContext.class)
      .insert(0, site, value)
      .cast(IRubyObject.class, MutableCallSite.class, long.class, ThreadContext.class)
      .invokeStaticQuiet(MethodHandles.lookup(), Bootstrap.class, "fixnum");
  site.setTarget(handle);
  return site;
}

public static CallSite flote(Lookup lookup, String name, MethodType type, double value) {
  MutableCallSite site = new MutableCallSite(type);
  MethodHandle handle = Binder
      .from(IRubyObject.class, ThreadContext.class)
      .insert(0, site, value)
      .cast(IRubyObject.class, MutableCallSite.class, double.class, ThreadContext.class)
      .invokeStaticQuiet(MethodHandles.lookup(), Bootstrap.class, "flote");
  site.setTarget(handle);
  return site;
}

/**
 * Cast the named argument to the given type.
 *
 * @param name the name of the argument to cast
 * @param type the type to which that argument will be cast
 * @return a new SmartBinder with the cast applied
 */
public SmartBinder castArg(String name, Class<?> type) {
  Signature newSig = signature().replaceArg(name, name, type);
  return new SmartBinder(this, newSig, binder.cast(newSig.type()));
}

/**
 * Cast the incoming arguments to the return and argument types given. The
 * argument count must match.
 *
 * @param returnType the return type for the casted signature
 * @param argTypes   the types of the arguments for the casted signature
 * @return a new SmartBinder with the cast applied
 */
public SmartBinder cast(Class<?> returnType, Class<?>... argTypes) {
  return new SmartBinder(this, new Signature(returnType, argTypes, signature().argNames()), binder.cast(returnType, argTypes));
}

private static MethodHandle createAttrReaderHandle(InvokeSite site, IRubyObject self, RubyClass cls, VariableAccessor accessor) {
  MethodHandle nativeTarget;
  MethodHandle filter = cls.getClassRuntime().getNullToNilHandle();
  MethodHandle getValue;
  if (accessor instanceof FieldVariableAccessor) {
    MethodHandle getter = ((FieldVariableAccessor)accessor).getGetter();
    getValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(Object.class, self.getClass()))
        .invoke(getter);
  } else {
    getValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(Object.class, Object.class))
        .prepend(accessor)
        .invokeVirtualQuiet(LOOKUP, "get");
  }
  // NOTE: Must not cache the fully-bound handle in the method, since it's specific to this class
  return getValue;
}

/**
 * Cast the return value to the given type.
 *
 * Example: Our current signature is (String)String but the method this
 * handle will eventually call returns CharSequence.
 *
 * <code>binder = binder.castReturn(CharSequence.class);</code>
 *
 * Our handle will now successfully find and call the target method and
 * propagate the returned CharSequence as a String.
 *
 * @param type the new type for the return value
 * @return a new SmartBinder
 */
public SmartBinder castReturn(Class<?> type) {
  return new SmartBinder(this, signature().changeReturn(type), binder.cast(type, binder.type().parameterArray()));
}

private static MethodHandle createAttrReaderHandle(InvokeSite site, IRubyObject self, RubyClass cls, VariableAccessor accessor) {
  MethodHandle nativeTarget;
  MethodHandle filter = cls.getClassRuntime().getNullToNilHandle();
  MethodHandle getValue;
  if (accessor instanceof FieldVariableAccessor) {
    MethodHandle getter = ((FieldVariableAccessor)accessor).getGetter();
    getValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(Object.class, self.getClass()))
        .invoke(getter);
  } else {
    getValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(Object.class, Object.class))
        .prepend(accessor)
        .invokeVirtualQuiet(LOOKUP, "get");
  }
  // NOTE: Must not cache the fully-bound handle in the method, since it's specific to this class
  return getValue;
}

    .from(IRubyObject.class, IRubyObject.class)
    .insert(1, cls.getRuntime().getNil())
    .cast(IRubyObject.class, IRubyObject.class, IRubyObject.class)
    .invokeStaticQuiet(lookup(), InvocationLinker.class, "valueOrNil");
  Class objCls = InvokeDynamicSupport.REIFIED_OBJECT_CLASSES[offset];
  nativeTarget = b
      .cast(Object.class, objCls)
      .getFieldQuiet(lookup(), "var" + offset);
} else {
      .filterReturn(filter)
      .insert(1, accessor.getIndex())
      .cast(Object.class, RubyBasicObject.class, int.class)
      .invokeStaticQuiet(lookup(), VariableAccessor.class, "getVariable");

    .from(IRubyObject.class, IRubyObject.class)
    .insert(1, cls.getRuntime().getNil())
    .cast(IRubyObject.class, IRubyObject.class, IRubyObject.class)
    .invokeStaticQuiet(lookup(), InvocationLinker.class, "valueOrNil");
  Class objCls = InvokeDynamicSupport.REIFIED_OBJECT_CLASSES[offset];
  nativeTarget = b
      .cast(Object.class, objCls)
      .getFieldQuiet(lookup(), "var" + offset);
} else {
      .filterReturn(filter)
      .insert(1, accessor.getIndex())
      .cast(Object.class, RubyBasicObject.class, int.class)
      .invokeStaticQuiet(lookup(), VariableAccessor.class, "getVariable");

private static MethodHandle createAttrWriterHandle(InvokeSite site, IRubyObject self, RubyClass cls, VariableAccessor accessor) {
  MethodHandle nativeTarget;
  MethodHandle filter = Binder
      .from(IRubyObject.class, Object.class)
      .drop(0)
      .constant(cls.getRuntime().getNil());
  MethodHandle setValue;
  if (accessor instanceof FieldVariableAccessor) {
    MethodHandle setter = ((FieldVariableAccessor)accessor).getSetter();
    setValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(void.class, self.getClass(), Object.class))
        .invoke(setter);
  } else {
    setValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(void.class, Object.class, Object.class))
        .prepend(accessor)
        .invokeVirtualQuiet(LOOKUP, "set");
  }
  return setValue;
}

private static MethodHandle createAttrWriterHandle(InvokeSite site, IRubyObject self, RubyClass cls, VariableAccessor accessor) {
  MethodHandle nativeTarget;
  MethodHandle filter = Binder
      .from(IRubyObject.class, Object.class)
      .drop(0)
      .constant(cls.getRuntime().getNil());
  MethodHandle setValue;
  if (accessor instanceof FieldVariableAccessor) {
    MethodHandle setter = ((FieldVariableAccessor)accessor).getSetter();
    setValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(void.class, self.getClass(), Object.class))
        .invoke(setter);
  } else {
    setValue = Binder.from(site.type())
        .drop(0, 2)
        .filterReturn(filter)
        .cast(methodType(void.class, Object.class, Object.class))
        .prepend(accessor)
        .invokeVirtualQuiet(LOOKUP, "set");
  }
  return setValue;
}

.cast(Object.class, IRubyObject.class)
.invokeStaticQuiet(lookup(), JavaUtil.class, "objectFromJavaProxy");
.filter(0, receiverConverter)
.filterReturn(filter)
.cast(fieldHandle.type())
.invoke(fieldHandle);
.cast(Object.class, IRubyObject.class)
.invokeStaticQuiet(lookup(), JavaUtil.class, "objectFromJavaProxy");
.filter(0, receiverConverter)
.filterReturn(constant(IRubyObject.class, self.getRuntime().getNil()))
.cast(fieldHandle.type())
.invoke(fieldHandle);

  Class objCls = InvokeDynamicSupport.REIFIED_OBJECT_CLASSES[offset];
  nativeTarget = b
      .cast(void.class, objCls, Object.class)
      .invokeStaticQuiet(lookup(), objCls, "setVariableChecked");
} else {
      .filterReturn(filter)
      .insert(1, cls.getRealClass(), accessor.getIndex())
      .cast(void.class, RubyBasicObject.class, RubyClass.class, int.class, Object.class)
      .invokeStaticQuiet(lookup(), accessor.getClass(), "setVariableChecked");

  Class objCls = InvokeDynamicSupport.REIFIED_OBJECT_CLASSES[offset];
  nativeTarget = b
      .cast(void.class, objCls, Object.class)
      .invokeStaticQuiet(lookup(), objCls, "setVariableChecked");
} else {
      .filterReturn(filter)
      .insert(1, cls.getRealClass(), accessor.getIndex())
      .cast(void.class, RubyBasicObject.class, RubyClass.class, int.class, Object.class)
      .invokeStaticQuiet(lookup(), accessor.getClass(), "setVariableChecked");

/**
 * Apply all transforms to an endpoint that does absolutely nothing. Useful for
 * creating exception handlers in void methods that simply ignore the exception.
 *
 * @return a handle that has all transforms applied and does nothing at its endpoint
 */
public MethodHandle nop() {
  if (type().returnType() != void.class) {
    throw new InvalidTransformException("must have void return type to nop: " + type());
  }
  return invoke(Binder
      .from(type())
      .drop(0, type().parameterCount())
      .cast(Object.class)
      .constant(null));
}

MethodHandle buildNewInstanceHandle(DynamicMethod method, IRubyObject self) {
  MethodHandle mh = null;
  if (method == self.getRuntime().getBaseNewMethod()) {
    RubyClass recvClass = (RubyClass) self;
    // Bind a second site as a dynamic invoker to guard against changes in new object's type
    CallSite initSite = SelfInvokeSite.bootstrap(LOOKUP, "callFunctional:initialize", type(), literalClosure ? 1 : 0, file, line);
    MethodHandle initHandle = initSite.dynamicInvoker();
    MethodHandle allocFilter = Binder.from(IRubyObject.class, IRubyObject.class)
        .cast(IRubyObject.class, RubyClass.class)
        .insert(0, new Class[] {ObjectAllocator.class, Ruby.class}, recvClass.getAllocator(), self.getRuntime())
        .invokeVirtualQuiet(LOOKUP, "allocate");
    mh = SmartBinder.from(LOOKUP, signature)
        .filter("self", allocFilter)
        .fold("dummy", initHandle)
        .permute("self")
        .identity()
        .handle();
    if (Options.INVOKEDYNAMIC_LOG_BINDING.load()) {
      LOG.info(name() + "\tbound as new instance creation " + Bootstrap.logMethod(method));
    }
  }
  return mh;
}

MethodHandle buildNewInstanceHandle(DynamicMethod method, IRubyObject self) {
  MethodHandle mh = null;
  if (method == self.getRuntime().getBaseNewMethod()) {
    RubyClass recvClass = (RubyClass) self;
    // Bind a second site as a dynamic invoker to guard against changes in new object's type
    CallSite initSite = SelfInvokeSite.bootstrap(LOOKUP, "callFunctional:initialize", type(), literalClosure ? 1 : 0, file, line);
    MethodHandle initHandle = initSite.dynamicInvoker();
    MethodHandle allocFilter = Binder.from(IRubyObject.class, IRubyObject.class)
        .cast(IRubyObject.class, RubyClass.class)
        .insert(0, new Class[] {ObjectAllocator.class, Ruby.class}, recvClass.getAllocator(), self.getRuntime())
        .invokeVirtualQuiet(LOOKUP, "allocate");
    mh = SmartBinder.from(LOOKUP, signature)
        .filter("self", allocFilter)
        .fold("dummy", initHandle)
        .permute("self")
        .identity()
        .handle();
    if (Options.INVOKEDYNAMIC_LOG_BINDING.load()) {
      LOG.info(name() + "\tbound as new instance creation " + Bootstrap.logMethod(method));
    }
  }
  return mh;
}