Newsgroups: comp.lang.apl
Path: watmath!watserv2.uwaterloo.ca!torn!utcsri!rpi!think.com!sdd.hp.com!elroy.jpl.nasa.gov!jato!csi!sam
From: sam@csi.jpl.nasa.gov (Sam Sirlin)
Subject: Re: box vs. nest
Message-ID: <1992Oct5.164822.23890@csi.jpl.nasa.gov>
Originator: sam@kalessin
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Organization: Jet Propulsion Laboratory, Pasadena, CA
References:  <921005051057_70530.1226_CHH4-3@CompuServe.COM>
Date: Mon, 5 Oct 1992 16:48:22 GMT
Lines: 32


In article <921005051057_70530.1226_CHH4-3@CompuServe.COM>, Mike Kent <70530.1226@CompuServe.COM> writes:
|> In article <1992Sep30.231307.21354@yrloc.ipsa.reuter.COM>,
|> loc@yrloc.ipsa.reuter.COM (Leigh Clayton) writes:
|> > ... the pervasion of functions into the depths of APL2 arrays has
|> > absolutely nothing to do with the definition of enclose ...
|> 
|> Not so.  The Dictionary enclose produces a result which is of a different
|> *datatype* from its argument (and all <'d arrays are of the same data
...
|> The pervasiveness of scalar functions
|> in APL2 is a consequence of two design decisions:  scalar extension
|> continues to apply to nested arrays; nesting does not produce new data
|> types.  

This would imply that APL2 doesn't allow the mixing of data types in
one array, as that would be a new data type. Personally I think that
is the main power of boxes - they introduce the structure concept
which is very powerful and useful. One simple, powerful example is the
self-documenting array. This surprises me as I thought you could do
anything with one system (without a loop) that you could do in the
other, and that that was Leigh's main point: basic philosophical
differences that nevertheless allow a one-to-one mapping aren't really
as significant as they seem.

While jihad may be fun for many, it's produced a stalemate for APL for
the last 10 years or so.

-- 
Sam Sirlin
Jet Propulsion Laboratory         sam@kalessin.jpl.nasa.gov

