n. An Algol-descended language designed by Niklaus Wirth
on the CDC 6600 around 1967--68 as an instructional tool for
elementary programming. This language, designed primarily to keep
students from shooting themselves in the foot and thus extremely
restrictive from a general-purpose-programming point of view, was
later promoted as a general-purpose tool and, in fact, became the
ancestor of a large family of languages including Modula-2 and
Ada (see also bondage-and-discipline language). The
hackish point of view on Pascal was probably best summed up by a
devastating (and, in its deadpan way, screamingly funny) 1981 paper
by Brian Kernighan (of K&R fame) entitled "Why Pascal is
Not My Favorite Programming Language", which was never formally
published but has circulated widely via photocopies. Part of his
discussion is worth repeating here, because its criticisms are
still apposite to Pascal itself after ten years of improvement and
could also stand as an indictment of many other
bondage-and-discipline languages. At the end of a summary of the
case against Pascal, Kernighan wrote:
9. There is no escape
This last point is perhaps the most important. The language is
inadequate but circumscribed, because there is no way to escape its
limitations. There are no casts to disable the type-checking when
necessary. There is no way to replace the defective run-time
environment with a sensible one, unless one controls the compiler that
defines the "standard procedures". The language is closed.
People who use Pascal for serious programming fall into a fatal trap.
Because the language is impotent, it must be extended. But each group
extends Pascal in its own direction, to make it look like whatever
language they really want. Extensions for separate compilation,
FORTRAN-like COMMON, string data types, internal static variables,
initialization, octal numbers, bit operators, etc., all add to the
utility of the language for one group but destroy its portability to
others.
I feel that it is a mistake to use Pascal for anything much beyond its
original target. In its pure form, Pascal is a toy language, suitable
for teaching but not for real programming.
Pascal has since been almost entirely displaced (by C) from the
niches it had acquired in serious applications and systems
programming, but retains some popularity as a hobbyist language in
the MS-DOS and Macintosh worlds.
