求助大家啊 急需这些翻译啊!能翻译多少翻译多少吧···谢谢大家了!
求助大家啊 急需这些翻译啊!能翻译多少翻译多少吧···谢谢大家了!
A type may be defined as an extension of another type.In this case,the behav-
ior specifications and type model of the super-type are inherited by it—there
is no need for any explicit retrieval.The subtype may extend the behavior by
defining new operations,or by providing additional specifications of inherited
operations—the specifications simply conjoin with the inherited specs.i.e.
there is no overriding of behavior specifications(in contrast to the traditional
overriding of method implementations for a subclass).
Class.A description of the internal design of an object:in program code,the
instance-variables and function bodies.In programming,an object is created as
an instance of a particular class.Some languages(like‘self’)do without
classes;but their designers still need types.
In a programming language,we may think of a class as implementing some
consciously designed types(which interact with client objects),and addition-
ally implementing a low-level type which represents its interface to the virtual-
machine which is the target of the language compiler.
Since the type(s)that a class implements had a behavior specification,the class
needs to meet that specification.The type utilized a type-model to provide the
vocabulary to define the actions.The class chooses certain instance variables
for its implementation.A retrieval is a mapping from the concrete to the
abstract.It establishes traceability and the correctness of the implementation
e.g.a design review would check the retrievals.
The figure below shows a type called SelectionList,which might be used in the
implementation of user selections for our CashRegister.It allows items to be
added,deleted,selected,and de-selected.The type model for specifying these
operations includes a concept of count,which item is at which position,and
which items are selected.There is also a convenience effect called movedUp,
which could be defined completely in terms of the other queries.
We also have a class named ListBoxA,and the retrieval to the type.As you can
see,the retrieval is a property of the implements relation between class and
type.In general,it is a property of any refines relationship,establishing the
mapping between two type-models(the queries and their corresponding types)
and the corresponding sets of actions.
那种直接翻译器我也知道啊 但是根本语句不通啊····能帮忙调整下逻辑吗