Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!unmvax!brainerd
From: brainerd@unmvax.unm.edu (Walt Brainerd)
Newsgroups: comp.lang.fortran
Subject: Re: dpANS Fortran 8x
Message-ID: <193@unmvax.unm.edu>
Date: 30 Jun 89 23:04:10 GMT
References: <2724@elxsi.UUCP> <6105@microsoft.UUCP>
Distribution: usa
Organization: University of New Mexico at Albuquerque
Lines: 59

In article <6105@microsoft.UUCP>, bobal@microsoft.UUCP (Bob Allison) writes:
> In article <2724@elxsi.UUCP> uunet!elxsi!corbett (Bob Corbett) writes:
> >
> >     One feature of Fortran 8x I find particularly annoying is that the type
> >definition facility permits only record types to be defined.  The lack of a
> >general type definition mechanism becomes even more irritating now that KIND
> >selectors have been added to the language.  Suppose a machine supports 64-bit
> >integers.  The Fortran 8x implementation for such a machine might permit
> >64-bit integer entities to be declared with a syntax such as
> >
> >		    INTEGER(64) :: entity-decl-list
> >
> >The number 64 is the kind selector.  Suppose a programmer is trying to write
> >a program for several different machines, and he or she has lots of data
> >object declarations for objects he or she wishes to be of the largest supported
> >integer type.  If the language supported a general type definition facility, he
> >or she could place a definition of a type, say LONGEST_INT, in an INCLUDE file,
> >and then use that type wherever it is needed.  The closest the current draft of
> >the standard will allow him or her to come to that solution is to allow a
> >definition of a structure containing a single field of the longest integer type
> > [...]
> 
> It turns out this is easily solvable: the kind parameter may be a parameter
> (that is, a symbolic constant):
> 
> 	INTEGER, PARAMETER :: MOST_INT_BITS = 64
> 	INTEGER(MOST_INT_BITS) :: entity-decl-list
> 
The request was for a user-defined type that does not involve structures.
What do parameters have to do with anything?

> However, it doesn't allow you to define a type, merely a type kind.  My
> personal resistance to that feature (contrary to Walt Brainerd's assertion
> that we're all morons who can't handle the concept) is that it doesn't mesh
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> well with the current rules of FORTRAN syntax: if we could define the first 
> token in each statement of an explicitle separated declaration section to 
> be a reserved keyword or a type (as in other languages which support this 
> feature), then I wouldn't have any problem.  However, FORTRAN has enough 
> areas already where the context just takes too long to resolve, and I am 
> reticent to introduce more areas.
> 
The evidence for my alleged implication is mounting!
(or maybe it's just me) but I don't understand what the first token of a
statement has to do with anything, either.  What I think is being requested
is the ability to do something like this (all statements begin with
a keyword):

TYPE LONGEST_INT 
INTEGER(64)  ! with or without a paramter
END TYPE LONGEST_INT

and then be able to declare
   
TYPE (LONGEST_INT) :: entity-decl-list

Walt Brainerd  Unicomp, Inc.  brainerd@unmvax.cs.unm.edu
-- 
Walt Brainerd  Unicomp, Inc.  brainerd@unmvax.cs.unm.edu