generations of programming languages

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A first-generation programming language is a machine-level programming language. It consists of 1s and 0s.

Originally, no translator was used to compile or assemble the first-generation language. The first-generation programming instructions were entered through the front panel switches of the computer system.

The main benefit of programming in a first-generation programming language is that code a user writes can run very fast and efficiently since it is directly executed by the CPU, but machine language is somewhat more difficult to learn than higher generational programming languages, and it is far more difficult to edit if errors occur, or, for example, if instructions need to be added into memory at some location, then all the instructions after the insertion point need to be moved down to make room in memory to accommodate the new instructions. Doing so on a front panel with switches can be very difficult. Furthermore portability is significantly reduced - in order to transfer code to a different computer it needs to be completely rewritten since the machine language for one computer could be significantly different from another computer. Architectural considerations make portability difficult too. For example, the number of registers on one CPU architecture could differ from those of another.

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A second-generation programming language is a term usually used to refer to some form of assembly language. Unlike first-generation programming languages, the code can be read and written fairly easily by a human, but it must be converted into a machine readable form in order to run on a computer. The conversion process is simply a mapping of the assembly language code into binary machine code (the first-generation language). The language is specific to and dependent on a particular processor family and environment. Since it is the native language of a processor it has significant speed advantages, but it requires more programming effort and is difficult to use effectively for large applications

3

A third generation language (3GL) is a programming language designed to be easier for a human to understand, including things like named variables. Fortran, ALGOL and COBOL are early examples of this sort of language. Most "modern" languages (BASIC, C, C++, Delphi, Java, and including COBOL, Fortran, ALGOL) are third generation. Most 3GLs support structured programming

4

A fourth-generation programming language (abbreviated 4GL) is a programming language designed with a specific purpose in mind, such as the development of commercial business software. Such languages arose after the introduction of modern, block-structured third-generation programming languages, which improved the process of software development. However, it was still considered by some to be frustrating, slow, and error prone to program computers. This led to the first "programming crisis", in which the amount of work that might be assigned to programmers greatly exceeded the amount of programmer time available to do it. Meanwhile, a lot of experience was gathered in certain areas, and it became clear that certain applications could be generalized by adding limited programming languages to them.

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A fifth-generation programming language (abbreviated 5GL) is a programming language based around solving problems using constraints given to the program, rather than using an algorithm written by a programmer. Most constraint-based and logic programming languages and some declarative languages are fifth-generation languages.

While fourth-generation programming languages are designed to build specific programs, fifth-generation languages are designed to make the computer solve the problem for you. This way, the programmer only needs to worry about what problems need to be solved and what conditions need to be met, without worrying about how to implement a routine or algorithm to solve them. Fifth-generation languages are used mainly in artificial intelligence research. Prolog, OPS5, and Mercury are the best known fifth-generation languages.

In the 1990s, fifth-generation languages were considered to be the wave of the future, and some predicted that they would replace all other languages for system development, with the exception of low-level languages. Most notably, Japan put much research and money into their fifth-generation computer systems project, hoping to design a massive computer network of machines using these tools.

However, as larger programs were built, the flaws of the approach became more apparent. It turns out that, starting from a set of constraints defining a particular problem, deriving an efficient algorithm to solve it is a very difficult problem in itself. This crucial step cannot yet be automated and still requires the insight of a human programmer.

Today, fifth-generation languages have lost part of their initial appeal and are mostly used in academic circles.


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