资料来源 : pyDict

法国哲学家计算机程式设计语言

资料来源 : WordNet®

pascal
     n 1: a unit of pressure equal to one newton per square meter
          [syn: {Pa}]
     2: French mathematician and philosopher and Jansenist; invented
        an adding machine; contributed (with Fermat) to the theory
        of probability (1623-1662) [syn: {Blaise Pascal}]
     3: a programing language designed to teach programming through
        a top-down modular approach

资料来源 : Free On-Line Dictionary of Computing

Pascal
     
         (After the French mathematician {Blaise Pascal}
        (1623-1662)) A programming language designed by {Niklaus
        Wirth} around 1970.  Pascal was designed for simplicity and
        for teaching programming, in reaction to the complexity of
        {ALGOL 68}.  It emphasises {structured programming}
        constructs, data structures and {strong typing}. Innovations
        included {enumeration types}, {subranges}, sets, {variant
        records}, and the {case statement}.  Pascal has been extremely
        influential in programming language design and has a great
        number of variants and descendants.
     
        ANSI/IEEE770X3.97-1993 is very similar to {ISO Pascal} but
        does not include {conformant arrays}.
     
        ISO 7185-1983(E).  Level 0 and Level 1.  Changes from Jensen &
        Wirth's Pascal include name equivalence; names must be bound
        before they are used; loop index must be local to the
        procedure; formal procedure parameters must include their
        arguments; {conformant array schema}s.
     
        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 Favourite 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 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, initialisation,
        {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.
     
        See also {Kamin's interpreters}, {p2c}.
     
        ["The Programming Language Pascal", N. Wirth, Acta Informatica
        1:35-63, 1971].
     
        ["PASCAL User Manual and Report", K. Jensen & N. Wirth,
        Springer 1975] made significant revisions to the language.
     
        [BS 6192, "Specification for Computer Programming Language
        Pascal", {British Standards Institute} 1982].
     
        [{Jargon File}]
     
        (1996-06-12)

Pascal-
     
        Pascal subset used in Brinch Hansen on Pascal Compilers, P.
        Brinch Hansen, P-H 1985.
     
        [{Jargon File}]