#include <stdlib.h>
#include <stdio.h>
#include "termmap.h"
#include "debug.h"
#include "memory.h"

//! Open termmaps code.
void
termmapsInit (void)
{
  return;
}

//! Close termmaps code.
void
termmapsDone (void)
{
  return;
}

//! Allocate memory for a termmap node.
/**
 *@return A pointer to uninitialised memory of the size of a termmap node.
 */
Termmap
makeTermmap (void)
{
  /* inline candidate */
  return (Termmap) memAlloc (sizeof (struct termmap));
}

//! Get function result
/**
 *@return Yields f(x), or -1 when it is not present.
 */
int
termmapGet (Termmap f, const Term x)
{
  while (f != NULL)
    {
      if (isTermEqual (x, f->term))
	return f->result;
      f = f->next;
    }
  return -1;
}

//! Add a value to a function.
/**
 *@return Adds f(x)=y to an existing function f. If f is NULL, a function is created. If x is already in the domain, the value is replaced.
 */
Termmap
termmapSet (const Termmap f, const Term x, const int y)
{
  Termmap fscan;

  //! Determine whether term already occurs
  fscan = f;
  while (fscan != NULL)
    {
      if (isTermEqual (x, fscan->term))
	{
	  //! Is the result correct already?
	  if (fscan->result != y)
	    fscan->result = y;
	  return f;
	}
      fscan = fscan->next;
    }
  //! Not occurred yet, make new node
  fscan = makeTermmap ();
  fscan->term = x;
  fscan->result = y;
  fscan->next = f;
  return fscan;
}

//! Duplicate a function
Termmap
termmapDuplicate (const Termmap f)
{
  if (f != NULL)
    {
      Termmap g;

      g = makeTermmap ();
      g->term = f->term;
      g->result = f->result;
      g->next = termmapDuplicate (f->next);
      return g;
    }
  else
    {
      return NULL;
    }
}

//! Delete a function
void
termmapDelete (const Termmap f)
{
  if (f != NULL)
    {
      termmapDelete (f->next);
      memFree (f, sizeof (struct termmap));
    }
}

//! Print a function
void
termmapPrint (Termmap f)
{
  if (f != NULL)
    {
      eprintf ("\"");
      termPrint (f->term);
      eprintf ("\" -> %i", f->result);
      if (f->next != NULL)
	{
	  eprintf (", ");
	  termmapPrint (f->next);
	}
    }
}