Lisp
LISt Processing language.
(Or mythically "Lots of Irritating Superfluous Parentheses").
{Artificial Intelligence}'s mother tongue, a symbolic,
{functional}, {recursive} language based on the ideas of
{lambda-calculus}, variable-length lists and trees as
fundamental data types and the interpretation of code as data
and vice-versa.
Data objects in Lisp are lists and {atom}s. Lists may contain
lists and atoms. Atoms are either numbers or symbols.
Programs in Lisp are themselves lists of symbols which can be
treated as data. Most implementations of Lisp allow functions
with {side-effect}s but there is a core of Lisp which is
{purely functional}.
All Lisp functions and programs are expressions that return
values; this, together with the high memory use of Lisp, gave
rise to {Alan Perlis}'s famous quip (itself a take on an Oscar
Wilde quote) that "Lisp programmers know the value of
everything and the cost of nothing".
The original version was {LISP 1}, invented by {John McCarthy}
at {MIT} in the late 1950s. Lisp is
actually older than any other {high level language} still in
use except {Fortran}. Accordingly, it has undergone
considerable change over the years. Modern variants are quite
different in detail. The dominant {HLL} among hackers until
the early 1980s, Lisp now shares the throne with {C}. See
{languages of choice}.
One significant application for Lisp has been as a proof by
example that most newer languages, such as {COBOL} and {Ada},
are full of unnecessary {crock}s. When the {Right Thing} has
already been done once, there is no justification for
{bogosity} in newer languages.
See also {Association of Lisp Users}, {Common Lisp}, {Franz
Lisp}, {MacLisp}, {Portable Standard Lisp}, {Interlisp},
{Scheme}, {ELisp}, {Kamin's interpreters}.
[{Jargon File}]
(1995-04-16)