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From: brendan@batserver.cs.uq.oz.au (Brendan Mahony)
Newsgroups: comp.society.futures
Subject: Re: C's sins of commission (was: (pssst...fortran?))
Message-ID: <4905@uqcspe.cs.uq.oz.au>
Date: 18 Sep 90 05:51:26 GMT
References: <1990Sep14.212806.8131@abcfd20.larc.nasa.gov -  <63218@lanl.gov>
Sender: news@uqcspe.cs.uq.oz.au
Reply-To: brendan@batserver.cs.uq.oz.au
Lines: 52

jlg@lanl.gov (Jim Giles) writes:

 - 1) 'Atomic' types (floats (various sizes), ints (various sizes), booleans,
 -    characters (various character sets), etc....)

 - 2) Enumerated data types.  These are simply a vay to allow the user to
 -    invent a new 'atomic' type.

 - 3) Arrays.  Mappings from a tuple of indices to a typed value.  Note: an
 -    array of arrays is legal and is _NOT_ the same as a 2-d array (although
 -    a little syntactic sugar could allow this later - no one has ever asked
 -    for it).

 - 4) Sequences.  An ordered collection of zero or more objects to be
 -    accessed in a specific order.  Obvious syntactic sugar (like direct
 -    referencing of the last element or an arbitrary element) is permitted.
 -    The usual implementation of character strings in C is an example of an
 -    inefficient implementation of a sequence.  You can have a sequence of
 -    any data type (including a sequence of sequences - which is what a
 -    dictionary is).

 - 5) Records.  Like C struct.  No difference at all really.

 - 6) Unions.  These are _always_ discriminated.  The compiler is
 -    responsible for maintaining and checking the type tags.  Note that
 -    this only _seems_ inefficient: _legal_ C programs should always
 -    explicitly maintain a tag anyway.

 - 7) Recursive types.  These may be given the attribute 'aliased' in order
 -    to allow circular and overlapping references.  Other than that, we have
 -    discussed these before.

 - In addition, all variables can be declared with a 'dynamic' attribute,
 - which means that they must be allocated before use (dynamic arrays give
 - their size at allocation time).  It might be desireable for sequences
 - and recursive data type to be given the dynamic attribute automatically.

 - I can demonstrate sample syntax for these if anyone thinks it is required.
 - Anyone who proposes a C data object that he claims is not representable
 - here is invited to do so (I'm not joking - I'm designing a language with
 - these features - this challenge is an attempt to find out whether I'm
 - leaving something out).

Yes you are. You are leaving out memory mapped I/O and operating system
vectors and other disgusting cludges that make the computing world go
round. Other than than you are spot on!

--
Brendan Mahony                   | brendan@batserver.cs.uq.oz       
Department of Computer Science   | heretic: someone who disgrees with you
University of Queensland         | about something neither of you knows
Australia                        | anything about.