Function IsCmd

Singular/iparith.cc:9760–9813

=================== general utilities ============================*/

/*=================== general utilities ============================*/
int IsCmd(const char *n, int & tok)
{
  int i;
  int an=1;
  int en=sArithBase.nLastIdentifier;

  loop
  //for(an=0; an<sArithBase.nCmdUsed; )
  {
    if(an>=en-1)
    {
      if (strcmp(n, sArithBase.sCmds[an].name) == 0)
      {
        i=an;
        break;
      }
      else if ((an!=en) && (strcmp(n, sArithBase.sCmds[en].name) == 0))
      {
        i=en;
        break;
      }
      else
      {
        // -- blackbox extensions:
        // return 0;
        return blackboxIsCmd(n,tok);
      }
    }
    i=(an+en)/2;
    if (*n < *(sArithBase.sCmds[i].name))
    {
      en=i-1;
    }
    else if (*n > *(sArithBase.sCmds[i].name))
    {
      an=i+1;
    }
    else
    {
      int v=strcmp(n,sArithBase.sCmds[i].name);
      if(v<0)
      {
        en=i-1;
      }
      else if(v>0)
      {
        an=i+1;
      }
      else /*v==0*/
      {
        break;
      }
    }
  }
  lastreserved=sArithBase.sCmds[i].name;
  tok=sArithBase.sCmds[i].tokval;
  if(sArithBase.sCmds[i].alias==2)