PL/I

Programming Language One, often referred to as PL / I ( PL / 1 PL1 or PLI) abbreviated is a programming language that was developed in the 1960s by IBM. The term PL / 1 is common, especially in Germany.

History of development

Originally PL ​​/ I was developed as a general programming language for all applications under the name of NPL (New Programming Language). An attempt was made to take advantage of all hitherto existing high-level languages ​​(in particular, Algol, Fortran and COBOL) to unite. Similarly, there was a goal, the dynamic memory management of assembler simplifies in PL / I integrate.

Properties

Critics of the language imputed PL / I, it was unfortunately only able to combine the disadvantages of the different models. In scientific and technical programmers, it was considered a commercial, commercial users in the natural sciences and technology. Trailers point to the advantages:

  • Syntax with free format
  • Keywords are not case -insensitive
  • Many built-in functions
  • Supports structured programming
  • Supports recursive programming
  • Datatypes are hardware independent
  • Dynamic memory management
  • Event handling

Implementations

PL / I was and still is in some large IBM users home language. Multics was written in PL / I.

Descendants of the PL / I are PL / M ( for microcomputers; major parts of CP / M were in PL / M written ) and PL / S ( IBM internal programming language for system software).

PL / I is used primarily on IBM mainframes, but there are also versions for Windows, OS / 2, AIX, and other Unix variants.

Compared to the later-developed languages ​​such as Pascal characterizes the whole of PL / I language family ( as it did the precursor of the ALGOL - Zoo), that data structures could be specified as concrete elements, but there were virtually no language elements for the definition of structure types. In the latest generation of PL / I of the company IBM Enterprise PL / I, and abstract data types can be used.

Program Example Hello World

Hello: proc options (main );        put list ( 'Hello world! ');   Hi end; see also

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