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Intrinsic Language of Syntax for Setting And Accessing Instance Variables in an Object-Oriented Environment

IP.com Disclosure Number: IPCOM000101096D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 119K

Publishing Venue

IBM

Related People

Butler, GG: AUTHOR [+2]

Abstract

Disclosed is the use of object name, instance variable and value, in that order, as a more natural syntax for setting or querying instance variables in an object-oriented programming message. With this syntax, no distinction need be made between data types and objects. The technique provides a mechanism that reduces code and eases code-comprehension.

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Intrinsic Language of Syntax for Setting And Accessing Instance Variables in an Object-Oriented Environment

       Disclosed is the use of object name, instance variable
and value, in that order, as a more natural syntax for setting or
querying instance variables in an object-oriented programming
message.  With this syntax, no distinction need be made between data
types and objects.  The technique provides a mechanism that reduces
code and eases code-comprehension.

      Object Oriented Programming languages are used in the
construction of systems with a windowing user interface. The
extension to programming languages completely changes the structure
of a program's internal design.  Opportunities exist for code
reduction, since objects should be shared in the same manner as
electronic components.

      In an Object Oriented Programming (OOP) language, the user uses
objects to construct the system.  Objects are grouped into classes,
in which all objects share the same set of properties and behavior.
Each object for a class ('instance') has its own values for the
properties of its class.  New classes of object may be simply defined
though these are generally derived from other classes.  Every object
has a set of values ('instance variables') which can be set or
queried.  No direct access is provided to these instance variables in
order to protect the object from corruption ('encapsulation').
Instead a 'message' (type of call) is sent to the object querying a
particular value or requesting the setting of a particular value.
Messages are also used to request specific actions such as the
displaying of the object, deletion of the object, etc.  Messages are
presented in a relatively standard fashion by today's Object Oriented
Programming languages:
   -  instance_name  action  -
Here the specific named object is required to perform a given action.
This action may be qualified by argument(s) (Parameter(s) in which
case it has the following form:
  -  instance_name  (arguments) action  -
Messages can be considered very similar to traditional function
calls, for example:
      function_name ( arguments )

      The function name corresponds to the action.  In messages the
instance name is separated out from the rest of the arguments.
However, the main difference is that the same message can be sent to
dif ferent classes of object (i.e. the name of the instance can
vary).  The only restriction is that each class so involved can
service the same message.  This flexibility is generally referred to
as 'late binding'.  Most programming languages only permit functions
to operate on a single data type specified in the function's
definition.  One exception is Application System Language (ASL) which
is part of IBM's Personal Application System (Personal AS) Pro...