#ifndef __functor_H
#define __functor_H
/*
 * Copyright (c) 2000 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form 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.
 *
 *    This program is distributed in the 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 this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */
#if !defined(WINNT)
#ident "$Id: functor.h,v 1.1 2001/03/11 00:29:38 steve Exp $"
#endif

# include  "pointers.h"
# include  <stdio.h>

typedef struct vvp_truth_s*vvp_truth_t;

/*
 * The vvp_ipoint_t is an integral type that is 32bits. The low 2 bits
 * select the port of the referenced functor, and the remaining 30
 * index the functor itself. All together, the 32 bits can completely
 * identify any input of any functor.
 *
 * Outputs of functors are the heads of a linked list of all the
 * inputs that it is connected to. The vvp_ipoint_t in .out points to
 * the first port in the list. The .port[x] in turn points to the next
 * port, and so on. The last .port[x] contains the null vvp_ipoint_t
 * value zero (0). In this way, an output can fan out as wide as the
 * original design requires.
 */

struct functor_s {
	/* This is the truth table for the device */
      vvp_truth_t table;
	/* This is the output for the device. */
      vvp_ipoint_t out;
	/* These are the input ports. */
      vvp_ipoint_t port[4];
};

typedef struct functor_s *functor_t;

/*
 * Initialize the functors address space. This function must be called
 * exactly once before any of the other functor functions may be
 * called.
 */
extern void functor_init(void);

/*
 * This function allocates a functor and returns the vvp_ipoint_t
 * address for it. Every call to functor_allocate is guaranteed to
 * return a different vvp_ipoint_t address. The ipoint port bits are 0.
 */
extern vvp_ipoint_t functor_allocate(void);

/*
 * Given an ipoint_t pointer, return a C pointer to the functor. This
 * is like a pointer dereference. The point parameter must have been
 * returned from a previous call to functor_allocate.
 */
extern functor_t functor_index(vvp_ipoint_t point);

/*
 * Dump a readable version of the functor address space to the file.
 */
extern void functor_dump(FILE*fd);

/*
 * $Log: functor.h,v $
 * Revision 1.1  2001/03/11 00:29:38  steve
 *  Add the vvp engine to cvs.
 *
 */
#endif