indexexpr.h

A C++ class library for scientific computing

// -*- C++ -*-
/***************************************************************************
 * blitz/indexexpr.h     Declaration of the IndexPlaceholder<N> class
 *
 * $Id: indexexpr.h,v 1.7 2005/05/07 04:17:56 julianc Exp $
 *
 * Copyright (C) 1997-2001 Todd Veldhuizen <[e-mail]>
 *
 * This program 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.
 *
 * This program 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.
 *
 * Suggestions:          [e-mail]
 * Bugs:                 [e-mail]
 *
 * For more information, please see the Blitz++ Home Page:
 *    p://seurat.uhttwaterloo.ca/blitz/
 *
 ***************************************************************************/

#ifndef BZ_INDEXEXPR_H
#define BZ_INDEXEXPR_H

#include <blitz/tinyvec.h>
#include <blitz/prettyprint.h>
#include <blitz/etbase.h>

BZ_NAMESPACE(blitz)

template<int N>
class IndexPlaceholder 
#ifdef BZ_NEW_EXPRESSION_TEMPLATES
  : public ETBase<IndexPlaceholder<N> > 
#endif
{
public:
    IndexPlaceholder()
    { }

#ifdef BZ_NEW_EXPRESSION_TEMPLATES
    IndexPlaceholder(const IndexPlaceholder<N>& x)
        : ETBase< IndexPlaceholder<N> >(x)
    { }
#else
    IndexPlaceholder(const IndexPlaceholder<N>&)
    { }
#endif

    ~IndexPlaceholder()
    { }

    void operator=(const IndexPlaceholder<N>&)
    { }

    typedef int T_numtype;
    typedef int T_ctorArg1;     // Dummy; not used
    typedef int T_ctorArg2;     // Ditto

    static const int 
        numArrayOperands = 0, 
        numIndexPlaceholders = 1,
        rank = N+1;

    // If you have a precondition failure on this routine, it means
    // you are trying to use stack iteration mode on an expression
    // which contains an index placeholder.  You must use index 
    // iteration mode instead.
    int operator*() { 
        BZPRECONDITION(0); 
        return 0;
    }

#ifdef BZ_ARRAY_EXPR_PASS_INDEX_BY_VALUE
    template<int N_rank>
    T_numtype operator()(TinyVector<int, N_rank> i) { return i[N]; }
#else
    template<int N_rank>
    T_numtype operator()(const TinyVector<int, N_rank>& i) { return i[N]; }
#endif

    int ascending(int) const { return INT_MIN; }
    int ordering(int)  const { return INT_MIN; }
    int lbound(int)    const { return INT_MIN; }  // tiny(int());
    int ubound(int)    const { return INT_MAX; }  // huge(int()); 

    // See operator*() note

    void push(int)       { BZPRECONDITION(0); }
    void pop(int)        { BZPRECONDITION(0); }
    void advance()       { BZPRECONDITION(0); }
    void advance(int)    { BZPRECONDITION(0); }
    void loadStride(int) { BZPRECONDITION(0); }

    bool isUnitStride(int) const { 
        BZPRECONDITION(0);
        return false;
    }

    void advanceUnitStride() { BZPRECONDITION(0); }

    bool canCollapse(int,int) const {   
        BZPRECONDITION(0); 
        return false; 
    }

    T_numtype operator[](int) {
        BZPRECONDITION(0);
        return T_numtype();
    }

    T_numtype fastRead(int) {
        BZPRECONDITION(0);
        return T_numtype();
    }

    int suggestStride(int) const {
        BZPRECONDITION(0);
        return 0;
    }

    bool isStride(int,int) const {
        BZPRECONDITION(0);
        return true;
    }

    void prettyPrint(BZ_STD_SCOPE(string) &str, prettyPrintFormat&) const {
        // NEEDS_WORK-- do real formatting for reductions
        str += "index-expr[NEEDS_WORK]";
    }

    template<typename T_shape>
    bool shapeCheck(const T_shape&) const { return true; }
};

typedef IndexPlaceholder<0> firstIndex;
typedef IndexPlaceholder<1> secondIndex;
typedef IndexPlaceholder<2> thirdIndex;
typedef IndexPlaceholder<3> fourthIndex;
typedef IndexPlaceholder<4> fifthIndex;
typedef IndexPlaceholder<5> sixthIndex;
typedef IndexPlaceholder<6> seventhIndex;
typedef IndexPlaceholder<7> eighthIndex;
typedef IndexPlaceholder<8> ninthIndex;
typedef IndexPlaceholder<9> tenthIndex;
typedef IndexPlaceholder<10> eleventhIndex;

#ifndef BZ_NO_TENSOR_INDEX_OBJECTS

BZ_NAMESPACE(tensor)
    _bz_global blitz::IndexPlaceholder<0> i;
    _bz_global blitz::IndexPlaceholder<1> j;
    _bz_global blitz::IndexPlaceholder<2> k;
    _bz_global blitz::IndexPlaceholder<3> l;
    _bz_global blitz::IndexPlaceholder<4> m;
    _bz_global blitz::IndexPlaceholder<5> n;
    _bz_global blitz::IndexPlaceholder<6> o;
    _bz_global blitz::IndexPlaceholder<7> p;
    _bz_global blitz::IndexPlaceholder<8> q;
    _bz_global blitz::IndexPlaceholder<9> r;
    _bz_global blitz::IndexPlaceholder<10> s;
    _bz_global blitz::IndexPlaceholder<11> t;
BZ_NAMESPACE_END // tensor

#endif

BZ_NAMESPACE_END

#endif // BZ_INDEXEXPR_H