recursion

Noun

WordNet 3.0

Noun (1)

(mathematics) an expression such that each term is generated by repeating a particular mathematical operation

Webster's Dictionary (GCIDE)

Recursion \Re*cur"sion\ (-sh?n), n. [L. recursio. See Recur.] The act of recurring; return. [Obs.] --Boyle. [1913 Webster]

Free On-line Dictionary of Computing

recursion mutually recursive mutual recursion recurse recursive

<mathematics, programming> When a function (or procedure) calls itself. Such a function is called "recursive". If the call is via one or more other functions then this group of functions are called "mutually recursive".

If a function will always call itself, however it is called, then it will never terminate. Usually however, it first performs some test on its arguments to check for a "base case" - a condition under which it can return a value without calling itself.

The canonical example of a recursive function is factorial:

factorial 0 = 1 factorial n = n * factorial (n-1)

Functional programming languages rely heavily on recursion, using it where a procedural language would use iteration.

(1996-05-11)

The Jargon File

recursion n.

See recursion. See also tail recursion.