source: git/Singular/dyn_modules/freealgebra/freealgebra.cc @ f006a1

#include "Singular/libsingular.h"

#ifdef HAVE_SHIFTBBA
static BOOLEAN freeAlgebra(leftv res, leftv args)
{
  const short t1[]={2,RING_CMD,INT_CMD};
  const short t2[]={3,RING_CMD,INT_CMD,INT_CMD};
  if (iiCheckTypes(args, t2, 0) || iiCheckTypes(args, t1, 1))
  {
    ring r=(ring)args->Data();
    int d=(int)(long)args->next->Data();
    if (d<2)
    {
      WerrorS("degree must be >=2");
      return TRUE;
    }
    int i=0;
    while(r->order[i]!=0)
    {
      if ((r->order[i]==ringorder_c) ||(r->order[i]==ringorder_C)) i++;
      else if ((r->block0[i]==1)&&(r->block1[i]==r->N)) i++;
      else
      {
        WerrorS("only for rings with a global ordering of one block");
        return TRUE;
      }
    }
    if ((r->order[i]!=0)
    || (rHasLocalOrMixedOrdering(r)))
    {
      WerrorS("only for rings with a global ordering of one block");
      //Werror("only for rings with a global ordering of one block,i=%d, o=%d",i,r->order[i]);
      return TRUE;
    }
    int ncGenCount = 0; 
    if (iiCheckTypes(args,t2,0))
      ncGenCount = (int)(long) args->next->next->Data();
    ring R=freeAlgebra(r,d,ncGenCount);
    res->rtyp=RING_CMD;
    res->data=R;
    return R==NULL;
  }
  return TRUE;
}

static BOOLEAN stest(leftv res, leftv args)
{
  const short t[]={2,POLY_CMD,INT_CMD};
  if (iiCheckTypes(args,t,1))
  {
    poly p=(poly)args->CopyD();
    args=args->next;
    int sh=(int)((long)(args->Data()));
    if (sh<0)
    {
      WerrorS("negative shift for pLPshift");
      return TRUE;
    }
    int L = pLastVblock(p);
    if (L+sh > currRing->N/currRing->isLPring)
    {
      WerrorS("pLPshift: too big shift requested\n");
      return TRUE;
    }
    p_LPshift(p,sh,currRing);
    res->data = p;
    res->rtyp = POLY_CMD;
    return FALSE;
  }
  else return TRUE;
}

static BOOLEAN btest(leftv res, leftv h)
{
  const short t[]={1,POLY_CMD};
  if (iiCheckTypes(h,t,1))
  {
    poly p=(poly)h->Data();
    res->rtyp = INT_CMD;
    res->data = (void*)(long)pLastVblock(p);
    return FALSE;
  }
  else return TRUE;
}

static BOOLEAN lpLmDivides(leftv res, leftv h)
{
  const short t1[]={2,POLY_CMD,POLY_CMD};
  const short t2[]={2,IDEAL_CMD,POLY_CMD};
  if (iiCheckTypes(h,t1,0))
  {
    poly p=(poly)h->Data();
    poly q=(poly)h->next->Data();
    res->rtyp = INT_CMD;
    res->data = (void*)(long)p_LPDivisibleBy(p, q, currRing);
    return FALSE;
  }
  else if (iiCheckTypes(h,t2,1))
  {
    ideal I=(ideal)h->Data();
    poly q=(poly)h->next->Data();
    res->rtyp = INT_CMD;
    for(int i=0;i<IDELEMS(I);i++)
    {
      if (p_LPDivisibleBy(I->m[i],q, currRing))
      {
        res->data=(void*)(long)1;
        return FALSE;
      }
    }
    res->data=(void*)(long)0;
    return FALSE;
  }
  else return TRUE;
}

static BOOLEAN lpVarAt(leftv res, leftv h)
{
  const short t[]={2,POLY_CMD,INT_CMD};
  if (iiCheckTypes(h,t,1))
  {
    poly p=(poly)h->Data();
    int pos=(int)((long)(h->next->Data()));
    res->rtyp = POLY_CMD;
    res->data = p_LPVarAt(p, pos, currRing);
    return FALSE;
  }
  else return TRUE;
}
#endif

//------------------------------------------------------------------------
// initialisation of the module
extern "C" int SI_MOD_INIT(freealgebra)(SModulFunctions* p)
{
#ifdef HAVE_SHIFTBBA
  p->iiAddCproc("freealgebra.so","freeAlgebra",FALSE,freeAlgebra);
  p->iiAddCproc("freealgebra.so","lpLmDivides",FALSE,lpLmDivides);
  p->iiAddCproc("freealgebra.so","lpVarAt",FALSE,lpVarAt);
  p->iiAddCproc("freealgebra.so","stest",TRUE,stest);
  p->iiAddCproc("freealgebra.so","btest",TRUE,btest);
#endif
  return (MAX_TOK);
}