Turing tarpit

A Turing tarpit (or Turing tar-pit) is any programming language or computer interface that allows for flexibility in function but is difficult to learn and use because it offers little or no support for common tasks.^[1] The phrase was coined in 1982 by Alan Perlis in the Epigrams on Programming:^[2]

54. Beware of the Turing tar-pit in which everything is possible but nothing of interest is easy.

In any Turing complete language, it is possible to write any computer program, so in a very rigorous sense nearly all programming languages are equally capable. However, having that theoretical ability is not the same as usefulness in practice. Turing tarpits are characterized by having a simple abstract machine that requires the user to deal with many details in the solution of a problem.^[3] At the extreme opposite are interfaces that can perform very complex tasks with little human intervention but become obsolete if requirements change slightly.

Some esoteric programming languages, such as Brainfuck or Malbolge, are specifically referred to as "Turing tarpits"^[4] because they deliberately implement the minimum functionality necessary to be classified as Turing complete languages. Using such languages is a form of mathematical recreation: programmers can work out how to achieve basic programming constructs in an extremely difficult but mathematically Turing-equivalent language.^[5]

• Greenspun's tenth rule
• Zawinski's law of software envelopment

• G. Fischer, A.C. Lemke, "Constrained Design Processes: Steps Toward Convivial Computing", Technical Report CU-CS-369-87, University of Colorado, USA.

• E.L. Hutchins, J.D. Hollan, D.A. Norman, Hutchins, Edwin L.; Hollan, James D.; Norman, Donald A. (1 December 1985). "Direct Manipulation Interfaces" (PDF). Human–Computer Interaction. 1 (4): 311–338. doi:10.1207/s15327051hci0104_2. Archived from the original (PDF) on 13 June 2010.. Also found in Donald A. Norman; Stephen W. Draper (1 January 1986). User Centered System Design: New Perspectives on Human-computer Interaction. Taylor & Francis. ISBN 978-0-89859-872-8.

• Esolangs, Turing Tarpit.