Programmer-defined data types, version 2

[Chris Hanson <cph>]

   Date: Fri, 1 Sep 89 08:42:07 -0700
   From: Morris J. Katz <katz@Polya.Stanford.EDU>

      Date: Thu, 31 Aug 89 18:15:50 edt
      From: cph@zurich.ai.mit.edu (Chris Hanson)

	 Date: Thu, 31 Aug 89 13:26:10 -0700
	 From: Morris J. Katz <katz@Polya.Stanford.EDU>

	 I might be swayed that it is important to leave the rest argument
	 position open for future extensions; but, I hardly buy that the
	 trade-off between 3 characters to form the list and one character per
	 symbol to make it into a symbol represents enough of a difference in
	 keystrokes to be important.  (My approach is actually shorter for
	 records of 1 or 2 fields (-:)

      Since I was obviously making an aesthetic argument, let's just
      summarize by saying I prefer the aesthetics of a single list argument.
      (I notice that you said nothing about my "abstraction" argument.)

   Maybe I am just being dense, but I am not sure to what you are
   refering in your abstraction argument.  It is for that reason that I
   did not respond to it. 

What I mean by being able to "abstract" on that argument is that its
value can by computed as an arbitrary expression.  I can easily
imagine circumstances where this is desirable.

On the other hand, I could do this with a rest argument by means of
`apply'; but I find that alternative clumsy and unattractive.
Furthermore, it feels like a kludge to compensate for the fact that
the "field list" no longer has any distinct identity.