[from ‘LISt Processing language’, but mythically from
‘Lots of Irritating Superfluous Parentheses’] AI's mother
tongue, a language based on the ideas of (a) variable-length lists and
trees as fundamental data types, and (b) the interpretation of code as data
and vice-versa. Invented by John McCarthy at MIT in the late 1950s, it is
actually older than any other HLL still in use
except FORTRAN. Accordingly, it has undergone considerable adaptive
radiation over the years; modern variants are quite different in detail
from the original LISP 1.5. The dominant HLL among hackers until the early
1980s, LISP has since shared the throne with C. Its
partisans claim it is the only language that is truly beautiful. See
languages of choice.
All LISP functions and programs are expressions that return values;
this, together with the high memory utilization of LISPs, 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”.
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
crocks. When the Right Thing
has already been done once, there is no justification for
bogosity in newer languages.
