Pascal Standards

Language standards were developed so that when code is written on one type of computer, or with one vendor's compiler, the code can be ported to another computer or compiler and still compile and run correctly. This is not a foolproof plan, however, as there are many unique behaviors of different computers. A program that invokes the unique behavior of a specific computer will have to be changed to work on another. Further, most computer environments offer libraries for performing commonly used functions. If the program makes several calls to the system libraries, those calls will most likely need to be replaced when porting the code to another computer, even if the compiler is fully compliant with its languages standards.

Although standards do not resolve the above issues, they do provide a certain amount of consistency within a language construct. The same code may not function, or perhaps even compile, when ported directly to another computer or compiler, but because the standards exist, a programmer familiar with that language will have a basic understanding of what the code is doing. Given an understanding of the libraries and unique properties of the computer to which the code is being ported, the task of porting the code is easier than if there were no language standards at all.

The first standard written for Pascal was developed in 1983, covering what is known as unextended Pascal (ISO 7185). In 1990, the same year that the unextended Pascal standard was updated, the Extended Pascal standard (ISO 10206) was established. The unextended Pascal standard incorporated basic functionality of the original Pascal, while the Extended Pascal standard was introduced to bring Pascal more in line with modern programming needs, thus providing the programmer a more powerful programming tool without sacrificing the elegance of Pascal.

To further meet the demands of the growing technology in computer programming, certain Pascal compilers were established to support Object-Oriented Programming. Although an official standard for Object Pascal has not been established at this writing, in 1993, the Pascal Standards Committee published an "Object-Oriented Extensions to Pascal" Technical Report which provides proposed standards. The members of the committee that assembled this report came from a variety of organizations - from Pace University and the US Air Force, to Apple Computer, Microsoft, and Digital Equipment Corporation. 

Finally, in 1995, John Reagan, a member of the ISO Pascal standards committee and compiler architect for Digital Equipment Corporation (now Compaq), composed a Pascal Standards FAQ. The FAQ addressed questions such as:

• What are the different Pascal standards?
• Who creates the standards?
• What are the required interfaces to Extended Pascal?
• What is the History of Pascal Standards?