Newsgroups: comp.lang.apl
Path: watmath!ljdickey
From: ljdickey@watmath.waterloo.edu (L. J. Dickey)
Subject: Expressiveness of Language
Message-ID: <1992Mar20.184205.4943@watmath.waterloo.edu>
Organization: University of Waterloo
References: <1992Mar19.190314.27860@csi.jpl.nasa.gov> <1992Mar19.220251.29999@cshl.org> <ROCKWELL.92Mar20072450@socrates.umd.edu>
Date: Fri, 20 Mar 1992 18:42:05 GMT
Lines: 68


Dan LaLiberte <iberte@cs.uiuc.edu> writes
 (1)--------------------------------------------------------------------
 |   I think the use of greek letters, heavy overloading, and character
 |   combinations in APL is a big mistake, and this mistake is only
 |   compounded by J and the proposed ASCII rendition of APL.
 | 
 |      .... more on the general subject of reducing the number of
 |    keystrokes being a silly goal at the expense of readability ...
 + ---------------------------------------------------------------------

and then Steve Roy <ssr@ama.caltech.edu writes:
 (2)---------------------------------------------------------------------
 |   Absolutly, positively correct.  I fail to see the point of reducing
 |   the whole suite of operators to every possible combination of
 |   punctuation marks.  Is this really supposed to be a language for
 |   Stephen Hawking, who is forced to "type" at less than a character per
 |   second?
 |   
 |   Come on guys, what is the point?
 + ---------------------------------------------------------------------

and LeRoy Davis <davisl@LOGDIS1.SM.AFLC.AF.MIL> answers:
 (3)--------------------------------------------------------------------
 | The "point" is (to quote Kenneth Iverson):
 | 
 |    "Applied mathematics is concerned with the design and analysis of
 |     algorithms or PROGRAMS.  The systematic treatment of complex algorithms
 |     requires a suitable PROGRAMMIWNG LANGUAGE for their description, and
 |     such a programming language should be concise, precise, consistent over
 |     a wide area of application, mnemonic, and economical of symbols..."
 | 
 | This is the introduction to "A Programming Language" and shows that the
 | "greek" characters are mathematical in origin.  The conciseness is that of
 | mathematical ideas.  Yes, I could write 5+5+5, but that is interchangeable
 | with 3x5.  The "point" is to have a language that readly facilitates the
 | manipulations of mathematical ideas.
 + ---------------------------------------------------------------------

I agree with Mr Davis and Dr.Iverson.

The opinions expressed in quotations (1) and (2) appear to be dominated
by lack of experience.  Those who have studied higher mathematics,
APL, or J, will have learned the power of expressiveness of notation
used in these languages.  In particular, the "silly goal" mentioned
above, is not to find just the minimal number of strokes to express
ideas, but to be able to solve larger problems.  To Davis's quotation
of Iverson, I would like to add these two, which come from a philospher
and from the the builder of a computing engine.


      By relieving the brain of all unnecessary work,
      a good notation sets it free to concentrate on
      more advanced problems, and in effect increases
      the mental power of the race.
                                       A.N. Whitehead

      The quantity of meaning compressed into small
      space by algebraic signs, is another circumstance
      that facilitates the reasonings we are accustomed
      to carry on by their aid.
                                       Charles Babbage

-- 
Leroy J. Dickey, Faculty of Mathematics, U of Waterloo, Canada  N2L 3G1
Internet:      ljdickey@watmath.UWaterloo.ca
               ljdickey@watmath.waterloo.edu
UUCP:          ljdickey@watmath.UUCP
