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// gf.cc: interface for NTL's ZZ_p
//////////////////////////////////////////////////////////////////////////
//
// Copyright 1990-2012 John Cremona
//
// This file is part of the eclib package.
//
// eclib is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at your
// option) any later version.
//
// eclib is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License
// along with eclib; if not, write to the Free Software Foundation,
// Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
//
//////////////////////////////////////////////////////////////////////////
#include <eclib/marith.h>
#include <eclib/gf.h>
map<ZZ,ZZ_pContext> ZZ_pContextCache;
galois_field::galois_field(void) //dummy
:q(to_ZZ(2))
{
// cout<<"In galois_field constructor, calling default ZZ_p::init(2)"<<endl;
ZZ_p::init(q);
}
galois_field::galois_field(const ZZ& qq)
:q(qq)
{
// cout<<"In galois_field constructor with q="<<qq<<endl;
map<ZZ,ZZ_pContext>::iterator t = ZZ_pContextCache.find(q);
if(t==ZZ_pContextCache.end())
{
// cout<<"Calling ZZ_p::init("<<q<<")"<<endl;
ZZ_p::init(q);
// cout<<"Storing ZZ_pContext for q="<<q<<endl;
ZZ_pContext c; c.save();
ZZ_pContextCache[q]=c;
}
else
{
// cout<<"Restoring ZZ_pContext for q="<<q<<endl;
t->second.restore();
}
}
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