REQUIRE "system.a4l";
(* => system.a4l, basemodel.a4l *)
PROVIDE "z-emptyfor.a4c";
(*
 * This file is part of the ASCEND Modeling Library and is released
 * under the GNU Public License as described at the end of this file.
 *)
(*
 * This file demonstrates how associative arrays of variables and relations
 * are handled in the case of definition over the empty set.
 * In version ascend IV 0.8 and all previous C versions, the handling
 * is inconsistent between FOR and non-FOR defined structures.
 *
 * The specified behavior is:
 * - all cases marked (* empty *) here should compile an empty array stub.
 * - all other cases should compile an array of the specified object even if,
 * as in the case of ra1 and ra2, that object is not mathematically
 * sensible. Productions such as ra1,ra2 should be allowed but warned
 * about vociferously.
 *
 * An action plan to bring the compiler up to the specification is not yet
 * in place, especially since the entire implementation strategy for
 * associative arrays and FOR statements needs to be redesigned due to
 * other problems in compiler instruction scheduling.
 *)

MODEL varfor;
  a[1..2] IS_A real;
  b[2..1] IS_A real; (* empty_*)
  FOR i IN [1..2] CREATE
	c[i] IS_A real;
  END FOR;

  FOR i IN [2..1] CREATE
	d[i] IS_A real; (* empty *)
  END FOR;
END varfor;

MODEL badrelfor;
 (* not allowed to have array of unindexed eqns. *)
 x IS_A generic_real;
 ra1[1..2]: x=2;
 ra2[2..1]: x=3; (* empty*)
END badrelfor;

MODEL relfor;
 x IS_A generic_real;
 FOR i IN [1..2] CREATE
   ra3[i]: x = i;
 END FOR;
 FOR i IN [2..1] CREATE
   ra4[i]: x = i;
 END FOR;
END relfor;

MODEL testfor;
  v IS_A varfor;
  r IS_A relfor;
END testfor;


(*
 *  z-emptyfor.a4c
 *  by Benjamin A Allan
 *  Part of the ASCEND Library
 *  $Date: 1998/06/17 19:39:35 $
 *  $Revision: 1.4 $
 *  $Author: mthomas $
 *  $Source: /afs/cs.cmu.edu/project/ascend/Repository/models/z-emptyfor.a4c,v $
 *
 *  This file is part of the ASCEND Modeling Library.
 *
 *  Copyright (C) 1998 Carnegie Mellon University
 *  Copyright (C) 1997 Benjamin A Allan
 *
 *  The ASCEND Modeling Library is free software; you can redistribute
 *  it and/or modify it under the terms of the GNU General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  The ASCEND Modeling Library is distributed in hope that it
 *  will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with the program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139 USA.
 *)