Computers

INTRODUCTION

Programming languages, by their own nature, are quickly created and changed. Every new niche, need, or market demands that new languages be invented to meet their requirements. A document, written in early 1995, listed nothing less than 2350 different languages.

Even with such abundance of languages, it's easy to see that many of them are just variations in overlapping programming concepts. In fact, as the aforementioned lists show, many of them are just variants of a base languages with a few new features thrown in to deal with some unknown demand. If we observe many of the languages created in the last ten years, we will notice that there was little evolution in conceptual terms. Perl, Python, PHP, Java, C, C++, C#, and Delphi exhibit few real differences among themselves. In most cases, those differences amount to nothing more than syntactic sugar, which changes the way some constructions are written without changing their meaning.

It's worth noting that many of the most used languages today have just gone beyond their procedural infancy. PHP is an obvious example. Other languages were already born as oriented-object languages, but didn't introduce any new concepts in their syntax and/or semantic domains. Python and Java are typical cases of those languages. That means many languages are just repeating history, trapped in an old evolutionary cycle.

DIFFERENT PROGRAMMING LANGUAGES

* ADA

* ALGOL

* BASIC

* C

* C++

* COBOL

* FORTRAN

* Java

* PROLOG

* Perl

ADA

ADA was established in 1983 and became a powerful, general-purpose language with built-in conccurrency, exception handling, generic templates, distributed execution, standard and de facto interfaces to other languages and libraries.

ADA is a computer programming language originally designed to support the construction of long-lived, highly reliable software systems. Its design emphasizes readability, avoids error-prone notation, encourages reuse and team coordination, and it is designed to be efficiently implementable.

ADA compiles to just about any OS out there. Strongly influenced by PASCAL, and at one time mandatory for Dept. of Defense software projects at the Pentagon.

ADA is a large, complex block-structured language aimed primarily at embedded computer applications. It has facilities for real-time response, concurrency, hardware access, and reliable run-time handling.

A significant advantage of Ada is its reduction of debugging time. Ada tries to catch as many errors as reasonably possible, as early as possible. Many errors are caught at compile-time by Ada that aren't caught or are caught much later by other computer languages. Ada programs also catch many errors at run-time if they can't be caught at compile-time (this checking can be turned off to improve performance if desired.

So much for the pros. Now the cons: it was designed by committee, its crockish, difficult to use, and overall a disastrous, multi-billion dollar boondoggle. Hackers find ADA's exception handling and interprocess communications features particularly hilarious.

The kindest thing that can be said, is that there is probably a good small language screaming to get out of it's elephantine bulk.

ALGOL

ALGOL is established in 1958 and it's the youngest, and probably most influential of the three big, classic languages, the other two being LISP [1959] and FORTRAN [1957].

The language is suitable for expressing a large class of numerical processor in a form sufficiently concise for direct automatic translation into the language of programmed automatic computers.The algorithmic language has three different kinds of representations- reference, hardware, and publication, and the development described is in terms of the language are represented by a given set of symbols and it is only in the choice of symbols that the other two representations may differ. Structure and content must be the same for all representations.

ALGOL 60- a portable language for scientific computations. ALGOL 60 is small and elegant. It is block-structured, nested, recursive, and free-form. It was also the first language to be described in BNF (Backus-Naur Form).

There are three lexical representations: hardware, reference, and publication. The only structured data types are arrays, but they are permitted to have lower bounds and could be dynamic. It also has conditional expressions, it introduced =, if, then, else ; very general "for' loops, switch declaration. Parameters are call-by-name and call-by-value. It has static local "own" variables. It lacks user-defined types, character manipulation and standard I/O.

Other ALGOL's are: ALGOL 68, ALGOL 68C, ALGOL 68R, ALGOL c,

ALGOL W, ALGOL X, ALGOL Y, ALGOL 58, ABC ALGOL.

BASIC

Language originally designed for Dartmouth's experimental timesharing system in the early 1960's [1964].

A novice can write short BASIC programs (10-12 lines) veryeasily, writing anything longer

a) is very painful, and

b) b) encourages bad habits that will make

it harder to use more powerful languages well.

Dijkstra observed in "selected Writings on Computing", "It is practically impossible to teach good programming style to students that have had prior exposure to BASIC: as potential programmers they are mentally mutilated beyond all hope of regeneration". And whereas every programming language has flaws, BASIC's are deep and many.

And as another great programmer once said,"This is what happens when a language designed as an educational toy is taken to seriously".

C

The C programming language and its direct descendants are by far the most popular programming