ptcover.c revision 3f54fd611f536639ec30dd53c48e5ec1897cc7d9
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 2000-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
#include "ptlib.h"
/*
* return the table cover of a over b
* the ranges in a that intersect with b
*/
Pt_t*
ptcover(Pt_t* a, Pt_t* b)
{
Pt_t* t;
Ptprefix_t* ap;
Ptprefix_t* bp;
if (!(t = ptopen(a->disc)))
return 0;
ap = (Ptprefix_t*)dtfirst(a->dict);
bp = (Ptprefix_t*)dtfirst(b->dict);
while (ap && bp)
{
if (ap->min > bp->max)
bp = (Ptprefix_t*)dtnext(b->dict, bp);
else
{
if (ap->max >= bp->min && !ptinsert(t, ap->min, ap->max))
break;
ap = (Ptprefix_t*)dtnext(a->dict, ap);
}
}
return t;
}