The central focus of Slice is on defining interfaces, for example:
Slice 的重点是定义接口，例如：
1 | module M |
This definition defines an interface type called Clock. The interface supports two operations: getTime and setTime. Clients access an object supporting the Clock interface by invoking an operation on the proxy for the object: to read the current time, the client invokes the getTime operation; to set the current time, the client invokes the setTime operation, passing an argument of type TimeOfDay.
此定义定义了一种称为 Clock 的接口类型。该接口支持两种操作：getTime 和 setTime。客户端通过在对象的代理上调用操作来访问支持 Clock 接口的对象：为了读取当前时间，客户端调用 getTime 操作;若要设置当前时间，客户端将调用 setTime 操作，并传递 TimeOfDay 类型的参数。
Invoking an operation on a proxy instructs the Ice run time to send a message to the target object. The target object can be in another address space or can be collocated (in the same process) as the caller — the location of the target object is transparent to the client. If the target object is in another (possibly remote) address space, the Ice run time invokes the operation via a remote procedure call; if the target is collocated with the client, the Ice run time bypasses the network stack altogether to deliver the request more efficiently.
在proxy上调用操作会指示 Ice 运行时向目标对象发送消息。目标对象可以位于另一个地址空间中，也可以与调用方并置（在同一进程中） — 目标对象的位置对客户端是透明的。如果目标对象位于另一个（可能是远程）地址空间中，则 Ice 运行时通过远程过程调用调用该操作;如果目标与客户端并置，则 Ice 运行时将完全绕过网络堆栈，以更有效地传递请求。
You can think of an interface definition as the equivalent of the public part of a C++ class definition or as the equivalent of a Java interface, and of operation definitions as (virtual) member functions. Note that nothing but operation definitions are allowed to appear inside an interface definition. In particular, you cannot define a type, an exception, or a data member inside an interface. This does not mean that your object implementation cannot contain state — it can, but how that state is implemented (in the form of data members or otherwise) is hidden from the client and, therefore, need not appear in the object’s interface definition.
您可以将接口定义视为 C++ 类定义的公共部分的等效项，或者是 Java 接口的等效项，并将操作定义视为（虚拟）成员函数。请注意，接口定义中只允许显示操作定义。具体而言，不能在接口内部定义类型、异常或数据成员。这并不意味着您的对象实现不能包含状态 — 它可以，但是该状态的实现方式（以数据成员或其他形式）对客户端是隐藏的，因此不需要出现在对象的接口定义中。
An Ice object has exactly one (most derived) Slice interface type. Of course, you can create multiple Ice objects that have the same type; to draw the analogy with C++, a Slice interface corresponds to a C++ class definition, whereas an Ice object corresponds to a C++ class instance (but Ice objects can be implemented in multiple different address spaces).
一个 Ice 对象只有一个（大多数派生的）Slice 接口类型。当然，您可以创建多个具有相同类型的 Ice 对象;为了与 C++ 进行类比，Slice 接口对应于 C++ 类定义，而 Ice 对象对应于 C++ 类实例（但 Ice 对象可以在多个不同的地址空间中实现）。
Ice also provides multiple interfaces for the same Ice object via a feature called facets.
Ice 还通过称为 facets 的功能为同一 Ice 对象提供多个接口。
A Slice interface defines the smallest grain of distribution in Ice: each Ice object has a unique identity (encapsulated in its proxy) that distinguishes it from all other Ice objects; for communication to take place, you must invoke operations on an object’s proxy. There is no other notion of an addressable entity in Ice. You cannot, for example, instantiate a Slice structure and have clients manipulate that structure remotely. To make the structure accessible, you must create an interface that allows clients to access the structure.
Slice 接口定义了 Ice 中最小的分布粒度：每个 Ice 对象都有一个唯一的身份（封装在其代理中），将其与所有其他 Ice 对象区分开来;要进行通信，必须在对象的代理上调用操作。Ice 中没有其他可寻址实体的概念。例如，您不能实例化 Slice 结构并让客户端远程操作该结构。要使结构易于访问，您必须创建一个允许客户端访问结构的接口。