Generations of programming languages

Programming languages have been classified into several programming language generations. Historically, this classification was used to indicate increasing power of programming styles. Later writers have somewhat redefined the meanings as distinctions previously seen as important became less significant to current practice.

A first-generation programming language is a machine-level programming language. 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 benefitof programming in a first-generation programming language is that the code a user writes can run very fast and efficiently, since it is directly executed by the CPU. However, machine language is a lot more difficult to learn than higher generational programming languages, and it is far more difficult to edit if errors occur.

Second-generation programming language is a generational way to categorize assembly languages. The term was coined to provide a distinction from higher level third-generation programming languages (3GL) such as COBOL and earlier machine code languages. Second-generation programming languages have the following properties:

• The code can be read and written by a programmer. To run on a computer it must be converted into a machine readable form, a process called assembly.

• The language is specific to a particular processor family and environment.

Second-generation languages are sometimes used in kernels and device drivers (though C is generally employed for this in modern kernels), but more often find use in extremely intensive processing such as games, video editing, graphic manipulation/rendering.

A third-generation programming language (3GL) is a refinement of a second-generation programming language. Whereas a second generation language is more aimed to fix logical structure to the language, a third generation language aims to refine the usability of the language in such a way to make it more user friendly. This could mean restructuring categories of possible functions to make it more efficient, condensing the overall bulk of code via classes (eg. Visual Basic). A third generation language improves over a second generation language by having more refinement on the usability of the language itself from the perspective of the user.

First introduced in the late 1950s, Fortran, ALGOL and COBOL are early examples of this sort of language. Most "modern" languages (BASIC, C, C++, C#, Pascal, and Java) are also third-generation languages. Most 3GLs support structured programming.

A fourth-generation programming language (1970s-1990) (abbreviated 4GL) is a programming language or programming environment designed with a specific purpose in mind, such as the development of commercial business software. In the evolution of computing, the 4GL followed the 3GL in an upward trend toward higher abstraction and statement power. The 4GL was followed by efforts to define and use a 5GL.

The natural-language, block-structured mode of the third-generation programming languages improved the process of software development. However, 3GL development methods can be slow and error-prone. It became clear that some applications could be developed more rapidly by adding a higher-level programming language and methodology which would generate the equivalent of very complicated 3GL instructions with fewer errors. In some senses, software engineering arose to handle 3GL development. 4GL and 5GL projects are more oriented toward problem solving and systems engineering.

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 a given problem without the programmer. 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 examples of fifth-generation languages.

Date: 2015-12-17; view: 825