PLearn 0.1
TMatRowsIterator_decl.h
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00001 // -*- C++ -*-
00002 
00003 // PLearn (A C++ Machine Learning Library)
00004 // Copyright (C) 1998 Pascal Vincent
00005 // Copyright (C) 1999-2002 Pascal Vincent, Yoshua Bengio and University of Montreal
00006 //
00007 
00008 // Redistribution and use in source and binary forms, with or without
00009 // modification, are permitted provided that the following conditions are met:
00010 // 
00011 //  1. Redistributions of source code must retain the above copyright
00012 //     notice, this list of conditions and the following disclaimer.
00013 // 
00014 //  2. Redistributions in binary form must reproduce the above copyright
00015 //     notice, this list of conditions and the following disclaimer in the
00016 //     documentation and/or other materials provided with the distribution.
00017 // 
00018 //  3. The name of the authors may not be used to endorse or promote
00019 //     products derived from this software without specific prior written
00020 //     permission.
00021 // 
00022 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00023 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00024 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00025 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00026 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00027 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00028 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00029 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00030 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00031 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00032 // 
00033 // This file is part of the PLearn library. For more information on the PLearn
00034 // library, go to the PLearn Web site at www.plearn.org
00035 
00036 
00037  
00038 
00039 /* *******************************************************      
00040  * $Id: TMatRowsIterator_decl.h 8235 2007-11-07 21:32:01Z nouiz $
00041  * AUTHORS: Pascal Vincent & Yoshua Bengio
00042  * This file is part of the PLearn library.
00043  ******************************************************* */
00044 
00045 
00048 #ifndef TMatRowsIterator_decl_INC
00049 #define TMatRowsIterator_decl_INC
00050 
00051 namespace PLearn {
00052 using namespace std;
00053 
00057 template <class T>
00058 class TMatRowsIterator
00059 {
00060 public:
00062     typedef random_access_iterator_tag iterator_category;
00063     typedef TVec<T>                    value_type;
00064     typedef ptrdiff_t                  difference_type;
00065     typedef TVec<T>*                   pointer;
00066     typedef TVec<T>&                   reference;
00067   
00068 private:
00069     T* ptr;                                    
00070     int width;                                 
00071     int mod;                                   
00072 
00073 public:
00074     TMatRowsIterator()
00075         : ptr(), width(), mod() {}
00076 
00077     TMatRowsIterator(T* p, int w, int m)
00078         : ptr(p), width(w), mod(m) {}
00079 
00080     // Implement trivial iterator functions
00081     bool operator==(const TMatRowsIterator& other) const {
00082         return ptr == other.ptr && width == other.width && mod == other.mod;
00083     }
00084 
00085     bool operator!=(const TMatRowsIterator& y)
00086     { return !operator==(y); }
00087 
00088     value_type operator*() {
00089         return TVec<T>(width, ptr);
00090     }
00091 
00092     // cannot define operator-> here since we cannot return a pointer to a
00093     // temporary (e.g. stack-based) vector and expect this to work properly...
00094   
00095     // Implement forward iterator functions
00096     TMatRowsIterator& operator++() {
00097         ptr += mod;
00098         return *this;
00099     }
00100 
00101     TMatRowsIterator operator++(int) {
00102         TMatRowsIterator r(*this);
00103         ptr += mod;
00104         return r;
00105     }
00106 
00107     // Implement bidirectional iterator functions
00108     TMatRowsIterator& operator--() {
00109         ptr -= mod;
00110         return *this;
00111     }
00112 
00113     TMatRowsIterator operator--(int) {
00114         TMatRowsIterator r(*this);
00115         ptr -= mod;
00116         return r;
00117     }
00118 
00119     // Implement random access iterator functions
00120     TMatRowsIterator& operator+=(difference_type n) {
00121         ptr += n*mod;
00122         return *this;
00123     }
00124 
00125     TMatRowsIterator operator+(difference_type n) {
00126         TMatRowsIterator r(*this);
00127         r += n;
00128         return r;
00129     }
00130   
00131     TMatRowsIterator& operator-=(difference_type n) {
00132         ptr -= n*mod;
00133         return *this;
00134     }
00135 
00136     TMatRowsIterator operator-(difference_type n) {
00137         TMatRowsIterator r(*this);
00138         r -= n;
00139         return r;
00140     }
00141 
00142     difference_type operator-(const TMatRowsIterator& y) {
00143         return (ptr - y.ptr) / mod;
00144     }
00145   
00146     value_type operator[](difference_type n) {
00147         return TVec<T>(width, ptr + n*mod);
00148     }
00149 
00150     bool operator<(const TMatRowsIterator& y) {
00151         return ptr < y.ptr;
00152     }
00153 
00154 };
00155 
00156 } // end of namespace PLearn
00157 
00158 #endif
00159 
00160 
00161 /*
00162   Local Variables:
00163   mode:c++
00164   c-basic-offset:4
00165   c-file-style:"stroustrup"
00166   c-file-offsets:((innamespace . 0)(inline-open . 0))
00167   indent-tabs-mode:nil
00168   fill-column:79
00169   End:
00170 */
00171 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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