ABC programming language

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ABC is an imperative general-purpose programming language and programming environment developed at CWI, Netherlands by Leo Geurts, Lambert Meertens, and Steven Pemberton. It is interactive, structured, high-level, and easy to learn and use, intended to be used instead of BASIC, Pascal, or even AWK. It is not a systems-programming language but is good for teaching or prototyping.

ABC has only five basic datatypes; strong typing, yet without need for declarations; explicit support for top-down programming; statement nesting by indentation. It provides infinite precision arithmetic, unlimited sized lists and strings, and other features supporting orthogonality and ease of use by novices. Its designers claim that ABC programs are typically around a quarter the size of the equivalent Pascal or C programs, and more readable.

ABC was originally a monolithic implementation, leading to an inability to adapt to new requirements, such as creating a Graphical User Interface. ABC could not directly access the underlying file system and operating system.

ABC includes a programming environment with syntax-directed editing, suggestions, persistent variables, and multiple workspaces.

1 Example
2 References
3 External links
- 3.1 Books

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Example

An example function words to collect the set of all words in a document:

HOW TO RETURN words document:
PUT {} IN collection
FOR line IN document:
   FOR word IN split line:
      IF word not.in collection:
         INSERT word IN collection
RETURN collection

ABC is available as an interpreter/compiler, currently version 1.05.02. ABC has been ported to Unix, DOS, Atari, and Apple Macintosh.

ABC also had a major influence on the design of the Python programming language; Guido van Rossum, who developed Python, previously worked for several years on the ABC system in the early 1980s [1] [2].

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