JargonFile/entries/Pascal.txt
2014-04-26 16:54:15 +01:00

40 lines
2.5 KiB
Plaintext

Pascal
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 turned down
by the technical journals but circulated widely via photocopies. It was
eventually published in Comparing and Assessing Programming Languages ,
edited by Alan Feuer and Narain Gehani (Prentice-Hall, 1984). Part of his
discussion is worth repeating here, because its criticisms are still
apposite to Pascal itself after many years of improvement and could also
stand as an indictment of many other bondage-and-discipline languages. (The
entire essay is available at http://www.lysator.liu.se/c/bwk-on-pascal.html.
) 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 entirely displaced (mainly by C ) from the niches it had acquired
in serious applications and systems programming, and from its role as a
teaching language by Java.