/*
   f98stack.h for f98stack.c
   Funge-98 Stack Stack C Functions - header.
   v0.98 Oct 1 1998 Chris Pressey
   v0.98a Mar 26 2003 Chris Pressey

   Copyright (c)1998, 2001, 2003, Cat's Eye Technologies.
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

     Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

     Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

     Neither the name of Cat's Eye Technologies nor the names of its
     contributors may be used to endorse or promote products derived
     from this software without specific prior written permission. 

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
   OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE. 

*/

#ifndef _F98STACK_H_
#define _F98STACK_H_

typedef struct Stack
{
  void * mem;        /* pointer to array of cells of any type */
  long int sp;       /* stack pointer */
  long int sc;       /* total stack capacity */
  long int dc;       /* data capacity of each cell */
} stack;

#ifdef DEBUG_STACK
  #include <stdio.h>
  #ifndef SDEBUG
    #define SDEBUG(x, s) fprintf(stderr, "<-Stack:%s->\n", x);           \
                         fprintf(stderr, "stack pointer: %ld\n", s->sp);  \
                         fprintf(stderr, "stack capacity: %ld\n", s->sc);  \
                         fprintf(stderr, "data capacity: %ld\n", s->dc);    \
                         fflush(stderr);
    #endif
  #else
  #ifndef SDEBUG
    #define SDEBUG(x, s)
    #endif
#endif

/* Given the number of cells (sc) and bytes per cell (dc), */
/* allocate a new stack */
extern stack *      stack_alloc(long int sc, long int dc);

/* Given a pointer to a stack, remove and return the top cell */
extern void *       stack_pop(stack * s);

/* Given a pointer to a stack and a value, place it on the */
/* top of the stack */
extern int          stack_push(stack * s, void * val);

/* Pop a series of cells off the stack as chars until a 0 cell */
extern void         stack_pop_string(stack * s, char * str);

/* Push a series of chars onto the stack as cells until a 0 char */
extern void         stack_push_string(stack * s, char * str);

/* Given a pointer to a stack and a number of cells from the top */
/* cell, return an indexed cell without removing it */
extern void *       stack_read(stack * s, int offset);

/* Return the number of cells on a given stack */
extern int          stack_measure(stack * s);

/* Remove all cells from a given stack */
extern void         stack_clear(stack * s);

/* Release all the memory used by a stack, invalidating the stack */
extern void         stack_free(stack * s);

/* Some handy definitions when working with stacks of stack *'s */

#define stack_stack_top(t)        (stack *)stack_read(t, 0)
#define stack_stack_pop(t)        (stack *)stack_pop(t)
#define stack_stack_push(t,s)     stack_push(t,(void *)s)
#define stack_stack_popcell(t)    stack_pop((stack *)stack_read(t, 0))
#define stack_stack_pushcell(t,s) stack_push((stack *)stack_read(t, 0),(void *)s)
#define stack_stack_popoffset(t,o) stack_pop((stack *)stack_read(t, o))
#define stack_stack_pushoffset(t,o,s) stack_push((stack *)stack_read(t, o),(void *)s)

extern int stack_stack_transfer (stack * t, int count, void * zero);

#endif /* _F98STACK_H_ not defined */