Computer Programming Languages (part 2) [Archives:2003/656/Education]

By Akram Yahia Baker
APTECH, Sana'a Center
Though FORTRAN was good at handling numbers, it was not so good at handling input and output, which mattered most to business computing. Business computing started to take off in 1959, and because of this, COBOL was developed. It was designed from the ground up as the language for businessmen. Its only data types were numbers and strings of text. It also allowed for these to be grouped into arrays and records, so that data could be tracked and organized better. It is interesting to note that a COBOL program is built in a way similar to an essay, with four or five major sections built into an elegant whole. COBOL statements also have a very English-like grammar, making it quite easy to learn. All of these features were designed to make it easier for the average business to learn and adopt it.
In 1958, John McCarthy of MIT created the List Processing (or LISP) language. It was designed for Artificial Intelligence (AI) research. Because it was designed for such a highly specialized field, its syntax had rarely been seen before or since. The most obvious difference between this language and other languages is that the basic and the only type of data is the list, denoted by a sequence of items enclosed by parentheses. LISP programs themselves are written as a set of lists, so that LISP has the unique ability to modify itself, and hence grow on its own. The LISP syntax was known as “Cambridge Polish”, as it was very different from standard Boolean logic (Wexelblat, 177):
x V y- Cambridge Polish, used to describe the LISP program
OR (x, y)-Parenthesized prefix notation, used in the LISP program
x OR y- standard Boolean logic
LISP remains in use today because it is highly specialized and is of an abstract nature.
The Algol language was created by a committee for scientific investigations and was used in 1958. It's major contribution was that it constituted the root of the tree that led to such languages as Pascal, C,C++, and Java. It was also the first language with a formal grammar, known as Backus-Naar Form or BNF (McGraw-Hill Encyclopedia of Science and Technology, 454). Though Algol implemented some novel concepts, such as recursive calling of functions, the next version of the language, Algol 68, became bloated and difficult to use (www.byte.com). This led to the adoption of smaller and more compact languages, such as Pascal.
Pascal was begun in 1968 by Niklaus Wirth. Its development was mainly out of necessity for a good teaching tool. In the beginning, the language designers had no hopes for it to enjoy widespread adoption. Instead, they concentrated on developing good tools for teaching such as a debugger and editing system and support for common early microprocessor machines which were in use in teaching institutions.

To be continued next week
——
[archive-e:656-v:13-y:2003-d:2003-08-04-p:education]