single assignment

Single assignment is used to describe a programming language or representation in which one can bind a value to a name at most once. It prevents some types of side effects, which is claimed to reduce software bugs and simplify debugging.
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single assignment
if a variable is only assigned a value once then an instance of that variable is thereafter semantically equivalent to the value. thus a single assignment language is a functional language
see also zero assignment.

<programming> A property of variables in a functional language. If a variable is only assigned a value once then an instance of that variable is thereafter semantically equivalent to the value.
See also zero assignment.
(2003-12-22)

<language> (SASL) A functional programming language designed by Professor David Turner in 1976 whilst at St. Andrews University. SASL is a derivative of ISWIM with infinite data structures. It is fully lazy but weakly typed. It was designed for teaching functional programming, with very simple syntax 1 ; n x fac(n-1)
A version of the expert system EMYCIN has been written in SASL.
SASL was originally known as "Saint Andrews Static Language". Not to be confused with SISAL.
ftp://a.cs.uiuc.edu/uiuc/kamin.distr/distr/sasl.p. See also Kamin's interpreters.
["A New Implementation Technique for Applicative Languages", D.A. Turner, Soft Prac & Exp 8:31-49 (1979)].
(2003-08-08)