/*************************************************************************
*									 *
*	 YAP Prolog 	%W% %G% 					 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		TermExt.h						 *
* mods:									 *
* comments:	Extensions to standard terms for YAP			 *
* version:      $Id: TermExt.h,v 1.15 2008-03-25 22:03:13 vsc Exp $	 *
*************************************************************************/

/**

@file TermExt.h

@page Extensions Extensions to Prolog

YAP includes a number of extensions over the original Prolog
language. Next, we discuss support to the most important ones.


 */


#ifdef USE_SYSTEM_MALLOC
#define SF_STORE  (&(Yap_heap_regs->funcs))
#else
#define SF_STORE  ((special_functors *)HEAP_INIT_BASE)
#endif

#if defined(USE_OFFSETS)
#define   AtomFoundVar ((Atom)(&(((special_functors *)(NULL))->AtFoundVar)))
#define   AtomFreeTerm ((Atom)(&(((special_functors *)(NULL))->AtFreeTerm)))
#define   AtomNil ((Atom)(&(((special_functors *)(NULL))->AtNil)))
#define   AtomDot ((Atom)(&(((special_functors *)(NULL))->AtDot)))
#elif OLD_STYLE_INITIAL_ATOMS
#define   AtomFoundVar AbsAtom((AtomEntry *)&(SF_STORE->AtFoundVar))
#define   AtomFreeTerm AbsAtom((AtomEntry *)&(SF_STORE->AtFreeTerm))
#define   AtomNil AbsAtom((AtomEntry *)&(SF_STORE->AtNil))
#define   AtomDot AbsAtom((AtomEntry *)&(SF_STORE->AtDot))
#else
#define   AtomFoundVar AbsAtom(SF_STORE->AtFoundVar)
#define   AtomFreeTerm AbsAtom(SF_STORE->AtFreeTerm)
#define   AtomNil AbsAtom(SF_STORE->AtNil)
#define   AtomDot AbsAtom(SF_STORE->AtDot)
#endif

#define   TermFoundVar MkAtomTerm(AtomFoundVar)
#define   TermFreeTerm MkAtomTerm(AtomFreeTerm)
#define   TermNil MkAtomTerm(AtomNil)
#define   TermDot MkAtomTerm(AtomDot)

typedef enum
{
  db_ref_e = sizeof (Functor *),
  attvar_e = 2*sizeof (Functor *),
  double_e = 3 * sizeof (Functor *),
  long_int_e = 4 * sizeof (Functor *),
  big_int_e = 5 * sizeof (Functor *),
  string_e = 6 * sizeof (Functor *)
}
blob_type;

#define   FunctorDBRef    ((Functor)(db_ref_e))
#define   FunctorAttVar   ((Functor)(attvar_e))
#define   FunctorDouble   ((Functor)(double_e))
#define   FunctorLongInt  ((Functor)(long_int_e))
#define   FunctorBigInt   ((Functor)(big_int_e))
#define   FunctorString   ((Functor)(string_e))
#define   EndSpecials     (string_e+sizeof(Functor *))

#include "inline-only.h"

#define IsAttVar(pt) __IsAttVar((pt) PASS_REGS)

INLINE_ONLY inline EXTERN int __IsAttVar (CELL *pt USES_REGS);

INLINE_ONLY inline EXTERN int
__IsAttVar (CELL *pt USES_REGS)
{
#ifdef YAP_H
  return (pt)[-1] == (CELL)attvar_e
    && pt < HR;
#else
  return (pt)[-1] == (CELL)attvar_e;
#endif
}

INLINE_ONLY inline EXTERN int GlobalIsAttVar (CELL *pt);

INLINE_ONLY inline EXTERN int
GlobalIsAttVar (CELL *pt)
{
  return (pt)[-1] == (CELL)attvar_e;
}

typedef enum
  {
    BIG_INT =      0x01,
    BIG_RATIONAL = 0x02,
    BIG_FLOAT =    0x04,
    EMPTY_ARENA =  0x10,
    ARRAY_INT =    0x21,
    ARRAY_FLOAT =  0x22,
    CLAUSE_LIST =  0x40,
    EXTERNAL_BLOB =  0x100, /* generic data */
    USER_BLOB_START =  0x1000, /* user defined blob */
    USER_BLOB_END =  0x1100 /* end of user defined blob */
  } 
big_blob_type;

INLINE_ONLY inline EXTERN blob_type BlobOfFunctor (Functor f);

INLINE_ONLY inline EXTERN blob_type
BlobOfFunctor (Functor f)
{
  return (blob_type) ((CELL)f);
}

typedef struct cp_frame {
  CELL *start_cp;
  CELL *end_cp;
  CELL *to;
#ifdef RATIONAL_TREES
  CELL oldv;
  int ground;
#endif
} copy_frame;


#ifdef COROUTINING

typedef struct
{
  /* what to do when someone tries to bind our term to someone else
     in some  predefined context */
  void (*bind_op) (Term *, Term CACHE_TYPE);
  /* what to do if someone wants to copy our constraint */
  int (*copy_term_op) (CELL *, struct cp_frame **, CELL * CACHE_TYPE);
  /* copy the constraint into a term and back */
  Term (*to_term_op) (CELL *);
  int (*term_to_op) (Term, Term CACHE_TYPE);
  /* op called to do marking in GC */
  void (*mark_op) (CELL *);
} ext_op;

/* known delays */
typedef enum
{
  empty_ext = 0 * sizeof (ext_op),	/* default op, this should never be called */
  attvars_ext = 1 * sizeof (ext_op)	/* support for attributed variables */
    /* add your own extensions here */
    /* keep this one */
}
exts;




#endif


#if defined(YAP_H)
/* make sure that these data structures are the first thing to be allocated
   in the heap when we start the system */
typedef struct special_functors_struct
{

#if 0
  struct ExtraAtomEntryStruct AtFoundVar;
  struct ExtraAtomEntryStruct AtFreeTerm;
  struct ExtraAtomEntryStruct AtNil;
  struct ExtraAtomEntryStruct AtDot;
#else
  struct AtomEntryStruct *AtFoundVar;
  struct AtomEntryStruct *AtFreeTerm;
  struct AtomEntryStruct *AtNil;
  struct AtomEntryStruct *AtDot;
#endif
}
special_functors;
#endif /* YAP_H */

INLINE_ONLY inline EXTERN Float CpFloatUnaligned(CELL *ptr);

#define MkFloatTerm(fl) __MkFloatTerm((fl) PASS_REGS)

INLINE_ONLY inline EXTERN Term __MkFloatTerm (Float USES_REGS);

INLINE_ONLY inline EXTERN Float FloatOfTerm (Term t);

#if SIZEOF_DOUBLE == SIZEOF_INT_P

INLINE_ONLY inline EXTERN Term
__MkFloatTerm (Float dbl USES_REGS)
{
  return (Term) ((HR[0] = (CELL) FunctorDouble, *(Float *) (HR + 1) =
		  dbl, HR[2] = EndSpecials, HR +=
		  3, AbsAppl (HR - 3)));
}


INLINE_ONLY inline EXTERN Float
FloatOfTerm (Term t)
{
  return (Float) (*(Float *) (RepAppl (t) + 1));
}



#define InitUnalignedFloat()

INLINE_ONLY inline EXTERN Float
CpFloatUnaligned(CELL *ptr)
{
  return *((Float *)ptr);
}

#else

#if SIZEOF_DOUBLE == 2*SIZEOF_INT_P

#define DOUBLE_ALIGNED(ADDR) ((CELL)(ADDR) & 0x4)

INLINE_ONLY EXTERN inline void
AlignGlobalForDouble( USES_REGS1 );

INLINE_ONLY EXTERN inline void
AlignGlobalForDouble( USES_REGS1 )
{
  /* Force Alignment for floats. Note that garbage collector may
     break the alignment; */
  if (!DOUBLE_ALIGNED(HR)) {
    RESET_VARIABLE(HR);
    HR++;
  }
}

#ifdef i386
INLINE_ONLY inline EXTERN Float
CpFloatUnaligned (CELL * ptr)
{
  return *((Float *) (ptr + 1));
}

#else
/* first, need to address the alignment problem */
INLINE_ONLY inline EXTERN Float
CpFloatUnaligned (CELL * ptr)
{
  union
  {
    Float f;
    CELL d[2];
  } u;
  u.d[0] = ptr[1];
  u.d[1] = ptr[2];
  return (u.f);
}

#endif

INLINE_ONLY inline EXTERN Term
__MkFloatTerm (Float dbl USES_REGS)
{
  return (Term) ((AlignGlobalForDouble ( PASS_REGS1 ), HR[0] =
		  (CELL) FunctorDouble, *(Float *) (HR + 1) = dbl, HR[3] =
		  EndSpecials, HR +=
		  4, AbsAppl (HR - 4)));
}


INLINE_ONLY inline EXTERN Float
FloatOfTerm (Term t)
{
  return (Float) ((DOUBLE_ALIGNED (RepAppl (t)) ? *(Float *) (RepAppl (t) + 1)
		   : CpFloatUnaligned (RepAppl (t))));
}


/* no alignment problems for 64 bit machines */
#else
     /* OOPS, YAP only understands Floats that are as large as cells or that
        take two cells!!! */

OOPS

#endif
#endif

#ifndef YAP_H
#include <stddef.h>
#endif


INLINE_ONLY inline EXTERN int IsFloatTerm (Term);

INLINE_ONLY inline EXTERN int
IsFloatTerm (Term t)
{
  return (int) (IsApplTerm (t) && FunctorOfTerm (t) == FunctorDouble);
}


/* extern Functor FunctorLongInt; */

#define MkLongIntTerm(i) __MkLongIntTerm((i) PASS_REGS)

INLINE_ONLY inline EXTERN Term __MkLongIntTerm (Int USES_REGS);

INLINE_ONLY inline EXTERN Term
__MkLongIntTerm (Int i USES_REGS)
{
  HR[0] = (CELL) FunctorLongInt;
  HR[1] = (CELL) (i);
  HR[2] =  EndSpecials;
  HR += 3;
  return AbsAppl(HR - 3);
}


INLINE_ONLY inline EXTERN Int LongIntOfTerm (Term t);

INLINE_ONLY inline EXTERN Int
LongIntOfTerm (Term t)
{
  return (Int) (RepAppl (t)[1]);
}



INLINE_ONLY inline EXTERN int IsLongIntTerm (Term);

INLINE_ONLY inline EXTERN int
IsLongIntTerm (Term t)
{
  return (int) (IsApplTerm (t) && FunctorOfTerm (t) == FunctorLongInt);
}


/****************************************************/

/*********** strings, coded as UTF-8 ****************/

#include <string.h>

/* extern Functor FunctorString; */

#define MkStringTerm(i) __MkStringTerm((i) PASS_REGS)

INLINE_ONLY inline EXTERN Term __MkStringTerm (const  char *s USES_REGS);

INLINE_ONLY inline EXTERN Term
__MkStringTerm (const  char *s USES_REGS)
{
  Term t = AbsAppl(HR);
  size_t sz = ALIGN_BY_TYPE(strlen((char *)s)+1,CELL);
  HR[0] = (CELL) FunctorString;
  HR[1] = (CELL) sz;
  strcpy((char *)(HR+2), (const char *)s);
  HR[2+sz] =  EndSpecials;
  HR += 3+sz;
  return t;
}

INLINE_ONLY inline EXTERN Term __MkUStringTerm (const unsigned char *s USES_REGS);

INLINE_ONLY inline EXTERN Term
__MkUStringTerm (const unsigned char *s USES_REGS)
{
  Term t = AbsAppl(HR);
  size_t sz = ALIGN_BY_TYPE(strlen((char *)s)+1,CELL);
  HR[0] = (CELL) FunctorString;
  HR[1] = (CELL) sz;
  strcpy((char *)(HR+2), (const char *)s);
  HR[2+sz] =  EndSpecials;
  HR += 3+sz;
  return t;
}


INLINE_ONLY inline EXTERN const unsigned char *UStringOfTerm (Term t);

INLINE_ONLY inline EXTERN const unsigned char *
UStringOfTerm (Term t)
{
  return (const unsigned char *) (RepAppl (t)+2);
}

INLINE_ONLY inline EXTERN const  char *StringOfTerm (Term t);

INLINE_ONLY inline EXTERN const  char *
StringOfTerm (Term t)
{
  return (const  char *) (RepAppl (t)+2);
}



INLINE_ONLY inline EXTERN int IsStringTerm (Term);

INLINE_ONLY inline EXTERN int
IsStringTerm (Term t)
{
  return (int) (IsApplTerm (t) && FunctorOfTerm (t) == FunctorString);
}



/****************************************************/

#ifdef USE_GMP

#include <stdio.h>

#ifdef __cplusplus
#include <gmpxx.h>
#else
#include <gmp.h>
#endif

#else

typedef UInt mp_limb_t;

typedef struct {
  Int _mp_size, _mp_alloc;
  mp_limb_t *_mp_d;
} MP_INT;

typedef struct {
  MP_INT _mp_num;
  MP_INT _mp_den;
} MP_RAT;

#endif

INLINE_ONLY inline EXTERN int IsBigIntTerm (Term);

INLINE_ONLY inline EXTERN int
IsBigIntTerm (Term t)
{
  return (int) (IsApplTerm (t) && FunctorOfTerm (t) == FunctorBigInt);
}

#ifdef USE_GMP

Term Yap_MkBigIntTerm(MP_INT *);
MP_INT *Yap_BigIntOfTerm(Term);

Term Yap_MkBigRatTerm(MP_RAT *);
MP_RAT *Yap_BigRatOfTerm(Term);

INLINE_ONLY inline EXTERN void MPZ_SET (mpz_t, MP_INT *);

INLINE_ONLY inline EXTERN void
MPZ_SET (mpz_t dest, MP_INT *src)
{
  dest->_mp_size = src->_mp_size;
  dest->_mp_alloc = src->_mp_alloc;
  dest->_mp_d = src->_mp_d;
}

INLINE_ONLY inline EXTERN int IsLargeIntTerm (Term);

INLINE_ONLY inline EXTERN int
IsLargeIntTerm (Term t)
{
  return (int) (IsApplTerm (t)
		&& ((FunctorOfTerm (t) <= FunctorBigInt)
		    && (FunctorOfTerm (t) >= FunctorLongInt)));
}


INLINE_ONLY inline EXTERN UInt Yap_SizeOfBigInt (Term);

INLINE_ONLY inline EXTERN UInt
Yap_SizeOfBigInt (Term t)
{
  CELL *pt = RepAppl(t)+1;
  return 2+(sizeof(MP_INT)+
	    (((MP_INT *)pt)->_mp_alloc*sizeof(mp_limb_t)))/sizeof(CELL);
}



#else



INLINE_ONLY inline EXTERN int IsLargeIntTerm (Term);

INLINE_ONLY inline EXTERN int
IsLargeIntTerm (Term t)
{
  return (int) (IsApplTerm (t) && FunctorOfTerm (t) == FunctorLongInt);
}



#endif

/* extern Functor FunctorLongInt; */

INLINE_ONLY inline EXTERN int IsLargeNumTerm (Term);

INLINE_ONLY inline EXTERN int
IsLargeNumTerm (Term t)
{
  return (int) (IsApplTerm (t)
		&& ((FunctorOfTerm (t) <= FunctorBigInt)
		    && (FunctorOfTerm (t) >= FunctorDouble)));
}

INLINE_ONLY inline EXTERN int IsExternalBlobTerm (Term, CELL);

INLINE_ONLY inline EXTERN int
IsExternalBlobTerm (Term t, CELL tag)
{
  return (int) (IsApplTerm (t) &&
		FunctorOfTerm (t) == FunctorBigInt &&
		RepAppl(t)[1] == tag);
}

INLINE_ONLY inline EXTERN void *ExternalBlobFromTerm (Term);

INLINE_ONLY inline EXTERN void *
ExternalBlobFromTerm (Term t)
{
  MP_INT *base = (MP_INT *)(RepAppl(t)+2);
  return (void *) (base+1);
}




INLINE_ONLY inline EXTERN int IsNumTerm (Term);

INLINE_ONLY inline EXTERN int
IsNumTerm (Term t)
{
  return (int) ((IsIntTerm (t) || IsLargeNumTerm (t)));
}




INLINE_ONLY inline EXTERN Int IsAtomicTerm (Term);

INLINE_ONLY inline EXTERN Int
IsAtomicTerm (Term t)
{
  return (Int) (IsAtomOrIntTerm (t) || IsLargeNumTerm (t));
}




INLINE_ONLY inline EXTERN Int IsExtensionFunctor (Functor);

INLINE_ONLY inline EXTERN Int
IsExtensionFunctor (Functor f)
{
  return (Int) (f <= FunctorString);
}



INLINE_ONLY inline EXTERN Int IsBlobFunctor (Functor);

INLINE_ONLY inline EXTERN Int
IsBlobFunctor (Functor f)
{
  return (Int) ((f <= FunctorString && f >= FunctorDBRef));
}



INLINE_ONLY inline EXTERN Int IsPrimitiveTerm (Term);

INLINE_ONLY inline EXTERN Int
IsPrimitiveTerm (Term t)
{
  return (Int) ((IsAtomOrIntTerm (t)
		 || (IsApplTerm (t) && IsBlobFunctor (FunctorOfTerm (t)))));
}

#ifdef TERM_EXTENSIONS


INLINE_ONLY inline EXTERN Int IsAttachFunc (Functor);

INLINE_ONLY inline EXTERN Int
IsAttachFunc (Functor f)
{
  return (Int) (FALSE);
}



#define IsAttachedTerm(t) __IsAttachedTerm(t PASS_REGS)

INLINE_ONLY inline EXTERN Int __IsAttachedTerm (Term USES_REGS);

INLINE_ONLY inline EXTERN Int
__IsAttachedTerm (Term t USES_REGS)
{
  return (Int) ((IsVarTerm (t) && IsAttVar(VarOfTerm(t))));
}

INLINE_ONLY inline EXTERN Int GlobalIsAttachedTerm (Term);

INLINE_ONLY inline EXTERN Int
GlobalIsAttachedTerm (Term t)
{
  return (Int) ((IsVarTerm (t) && GlobalIsAttVar(VarOfTerm(t))));
}

#define SafeIsAttachedTerm(t) __SafeIsAttachedTerm((t) PASS_REGS)

INLINE_ONLY inline EXTERN Int __SafeIsAttachedTerm (Term USES_REGS);

INLINE_ONLY inline EXTERN Int
__SafeIsAttachedTerm (Term t USES_REGS)
{
  return (Int) (IsVarTerm (t) && IsAttVar(VarOfTerm(t)));
}

INLINE_ONLY inline EXTERN exts ExtFromCell (CELL *);

INLINE_ONLY inline EXTERN exts
ExtFromCell (CELL * pt)
{
  return attvars_ext;
}



#else


INLINE_ONLY inline EXTERN Int IsAttachFunc (Functor);

INLINE_ONLY inline EXTERN Int
IsAttachFunc (Functor f)
{
  return (Int) (FALSE);
}




INLINE_ONLY inline EXTERN Int IsAttachedTerm (Term);

INLINE_ONLY inline EXTERN Int
IsAttachedTerm (Term t)
{
  return (Int) (FALSE);
}




#endif

INLINE_ONLY inline EXTERN Int Yap_BlobTag(Term t);

INLINE_ONLY inline EXTERN Int Yap_BlobTag(Term t)
{
  CELL *pt = RepAppl(t);

  return pt[1];
}


INLINE_ONLY inline EXTERN void *Yap_BlobInfo(Term t);

INLINE_ONLY inline EXTERN void *Yap_BlobInfo(Term t)
{
  MP_INT *blobp;
  CELL *pt = RepAppl(t);

  blobp = (MP_INT *)(pt+2);
  return (void *)(blobp+1);
}

#ifdef YAP_H

INLINE_ONLY inline EXTERN int unify_extension(Functor, CELL, CELL *, CELL);

EXTERN int unify_extension(Functor, CELL, CELL *, CELL);

int   Yap_gmp_tcmp_big_big(Term, Term);

INLINE_ONLY inline EXTERN int
unify_extension (Functor f, CELL d0, CELL * pt0, CELL d1)
{
  switch (BlobOfFunctor (f))
    {
    case db_ref_e:
      return (d0 == d1);
    case attvar_e:
      return (d0 == d1);
    case long_int_e:
      return (pt0[1] == RepAppl (d1)[1]);
    case string_e:
      return strcmp( (char *)(pt0+2), (char *)(RepAppl (d1)+2) ) == 0;
    case big_int_e:
#ifdef USE_GMP
      return (Yap_gmp_tcmp_big_big(d0,d1) == 0);
#else
      return d0 == d1;
#endif /* USE_GMP */
    case double_e:
      {
	CELL *pt1 = RepAppl (d1);
	return (pt0[1] == pt1[1]
#if SIZEOF_DOUBLE == 2*SIZEOF_INT_P
		&& pt0[2] == pt1[2]
#endif
	  );
      }
    }
  return (FALSE);
}

static inline
CELL Yap_IntP_key(CELL *pt)
{
#ifdef USE_GMP
  if (((Functor)pt[-1] == FunctorBigInt)) {
    MP_INT *b1 = Yap_BigIntOfTerm(AbsAppl(pt-1));
    /* first cell in program */
    CELL val = ((CELL *)(b1+1))[0];
    return MkIntTerm(val & (MAX_ABS_INT-1));
  }
#endif
  return MkIntTerm(pt[0] & (MAX_ABS_INT-1));
}

static inline
CELL Yap_Int_key(Term t)
{
  return Yap_IntP_key(RepAppl(t)+1);
}

static inline
CELL Yap_DoubleP_key(CELL *pt)
{
#if SIZEOF_DOUBLE1 == 2*SIZEOF_INT_P
  CELL val = pt[0]^pt[1];
#else
  CELL val = pt[0];
#endif
  return MkIntTerm(val & (MAX_ABS_INT-1));  
}

static inline
CELL Yap_Double_key(Term t)
{
  return Yap_DoubleP_key(RepAppl(t)+1);
}

static inline
CELL Yap_StringP_key(CELL *pt)
{
  UInt n = pt[1], i;
  CELL val = pt[2];
  for (i=1; i<n; i++) {
    val ^= pt[i+1];
  }
  return MkIntTerm(val & (MAX_ABS_INT-1));  
}

static inline
CELL Yap_String_key(Term t)
{
  return Yap_StringP_key(RepAppl(t)+1);
}

#endif