/*
Copyright (c) 2003, Dan Kranz and Arnold Rom
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.

    * The names of its contributors may not 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 COPYRIGHT OWNER 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.
*/

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <roots.h>

/* ############################################################################# */
/* #                     SETPRN(STRING,FIRST,LNEXTL,MATCH)                     # */
/* #                                                                           # */
/* #  Purpose                                                                  # */
/* #  -------                                                                  # */
/* #  Use  SETPRN  to  split  an  input  sub-list into two mutually exclusive  # */
/* #  output   sublists.    In   particular,  SETPRN  scans  each  member  of  # */
/* #  FIRST,LNEXTL;  each  member has an inherent LINE number which may range  # */
/* #  from 1 to NLINE.  SETPRN uses the LINE numbers to address bit positions  # */
/* #  in STRING.                                                               # */
/* #                                                                           # */
/* #  Members  whose  STRING(LINE) contain a "1" are moved to output sub-list  # */
/* #  MATCH,LNEXTL.  Members  whose  STRING(LINE)  contain  a  "0"  remain in  # */
/* #  FIRST,LNEXTL.                                                            # */
/* #                                                                           # */
/* #  Note: SETPRN is used typically in conjunction with SETBIT.               # */
/* #                                                                           # */
/* #  The calling arguments to the current routine are as follows:             # */
/* #  -----------------------------------------------------------              # */
/* #  STRING - is a LOGICAL*1 array containing a bit vector.                   # */
/* #                                                                           # */
/* #  FIRST  - contains the first member of the input sub-list.                # */
/* #                                                                           # */
/* #  LNEXTL - is a half-word array containing the input linked list.          # */
/* #                                                                           # */
/* #  MATCH  - contains the first member of the matching output sub-list.      # */
/* #                                                                           # */
/* #           Output  MATCH,LNEXTL  will  contain members whose STRING(LINE)  # */
/* #           contain a "1"                                                   # */
/* #                                                                           # */
/* #           Output FIRST,LNEXTL will contain the leftovers.                 # */
/* #                                                                           # */
/* #  Note: the input sort sequence is preserved in both output sublists.      # */
/* ############################################################################# */

/* small internal routines */

static void sos(void) {RootsSOS("setprn sos exit\n"); abort();}

void setprn(
                      BYTE *string,
                      long *first,
                      unsigned short *lnextl,
                      long *match
                      )

/* --------------------------------------------------------- */
{       /* setprn START */
/* --------------------------------------------------------- */

/*      local data */

        long guard=MAXLIN,LastMatch;

        long CurrentInputLine,PreviousInputLine,NextInputLine;
        BYTE tbits[8]= {0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};

/* -------------------------------- */
/*      setup */
/* -------------------------------- */

        PreviousInputLine=LastMatch=*match=0;

        if((CurrentInputLine=*first)==0)return;
        if(CurrentInputLine<0)sos();

        --lnextl;

/* ------------------------------------ */
/*      process all members of lnextl */
/* ------------------------------------ */

        while(CurrentInputLine>0)
        {
        if(!guard--)sos();

/*      ----------------------------------------------------------------- */
/*      advance to next input member if CurrentInputLine's bit is off */
/*      ----------------------------------------------------------------- */

        if(!( *(string+( (CurrentInputLine-1) >>3) )
               &
               tbits[ (CurrentInputLine-1) & 0x7]
            )
          )
                                 {
                                 PreviousInputLine=CurrentInputLine;
                                 CurrentInputLine=*(lnextl+CurrentInputLine);
                                 continue;
                                 }

/*      ----------------------------------------------------------------- */
/*      bit(CurrentInputLine)==1) */
/*      ----------------------------------------------------------------- */

        RemoveFromInputList(first,lnextl,CurrentInputLine,PreviousInputLine,
                                                              NextInputLine)

        InsertIntoOutputList(match,lnextl,CurrentInputLine,LastMatch)

/*      step */

        CurrentInputLine=NextInputLine;
        }

        return;
/* --------------------------------------------------------- */
}       /* setprn END */
/* --------------------------------------------------------- */