1 | // -*- C++ -*- |
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2 | /*************************************************************************** |
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3 | * blitz/range.h Declaration of the Range class |
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4 | * |
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5 | * $Id: range.h,v 1.9 2005/05/07 04:17:56 julianc Exp $ |
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6 | * |
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7 | * Copyright (C) 1997-2001 Todd Veldhuizen <tveldhui@oonumerics.org> |
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8 | * |
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9 | * This program is free software; you can redistribute it and/or |
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10 | * modify it under the terms of the GNU General Public License |
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11 | * as published by the Free Software Foundation; either version 2 |
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12 | * of the License, or (at your option) any later version. |
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13 | * |
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14 | * This program is distributed in the hope that it will be useful, |
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15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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17 | * GNU General Public License for more details. |
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18 | * |
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19 | * Suggestions: blitz-dev@oonumerics.org |
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20 | * Bugs: blitz-bugs@oonumerics.org |
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21 | * |
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22 | * For more information, please see the Blitz++ Home Page: |
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23 | * http://oonumerics.org/blitz/ |
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24 | * |
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25 | ***************************************************************************/ |
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26 | |
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27 | #ifndef BZ_RANGE_H |
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28 | #define BZ_RANGE_H |
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29 | |
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30 | #ifndef BZ_BLITZ_H |
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31 | #include <blitz/blitz.h> |
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32 | #endif |
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33 | |
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34 | #ifndef BZ_VECEXPRWRAP_H |
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35 | #include <blitz/vecexprwrap.h> // _bz_VecExpr wrapper |
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36 | #endif |
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37 | |
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38 | #include <blitz/wrap-climits.h> // for INT_MIN |
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39 | |
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40 | BZ_NAMESPACE(blitz) |
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41 | |
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42 | // Examples: |
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43 | // Vector<double> x(7); |
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44 | // Range::all() [0,1,2,3,4,5,6] |
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45 | // Range(3,5) [3,4,5] |
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46 | // Range(3,Range::toEnd) [3,4,5,6] |
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47 | // Range(Range::fromStart,3) [0,1,2,3] |
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48 | // Range(1,5,2); [1,3,5] |
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49 | |
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50 | enum { fromStart = INT_MIN, toEnd = INT_MIN }; |
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51 | |
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52 | // Class Range |
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53 | class Range { |
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54 | |
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55 | public: |
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56 | // This declaration not yet supported by all compilers |
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57 | // const int fromStart = INT_MIN; |
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58 | // const int toEnd = INT_MIN; |
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59 | |
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60 | typedef int T_numtype; |
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61 | |
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62 | enum { fromStart = INT_MIN, toEnd = INT_MIN }; |
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63 | |
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64 | Range() |
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65 | { |
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66 | first_ = fromStart; |
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67 | last_ = toEnd; |
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68 | stride_ = 1; |
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69 | } |
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70 | |
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71 | // Range(Range r): allow default copy constructor to be used |
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72 | #ifdef BZ_MANUAL_VECEXPR_COPY_CONSTRUCTOR |
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73 | Range(const Range& r) |
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74 | { |
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75 | first_ = r.first_; |
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76 | last_ = r.last_; |
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77 | stride_ = r.stride_; |
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78 | } |
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79 | #endif |
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80 | |
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81 | explicit Range(int slicePosition) |
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82 | { |
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83 | first_ = slicePosition; |
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84 | last_ = slicePosition; |
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85 | stride_ = 1; |
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86 | } |
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87 | |
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88 | Range(int first, int last, int stride=1) |
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89 | : first_(first), last_(last), stride_(stride) |
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90 | { |
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91 | BZPRECHECK((first == fromStart) || (last == toEnd) || |
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92 | (first < last) && (stride > 0) || |
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93 | (first > last) && (stride < 0) || |
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94 | (first == last), (*this) << " is an invalid range."); |
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95 | BZPRECHECK((last-first) % stride == 0, |
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96 | (*this) << ": the stride must evenly divide the range"); |
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97 | } |
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98 | |
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99 | int first(int lowRange = 0) const |
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100 | { |
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101 | if (first_ == fromStart) |
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102 | return lowRange; |
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103 | return first_; |
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104 | } |
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105 | |
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106 | int last(int highRange = 0) const |
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107 | { |
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108 | if (last_ == toEnd) |
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109 | return highRange; |
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110 | return last_; |
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111 | } |
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112 | |
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113 | unsigned length(int =0) const |
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114 | { |
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115 | BZPRECONDITION(first_ != fromStart); |
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116 | BZPRECONDITION(last_ != toEnd); |
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117 | BZPRECONDITION((last_ - first_) % stride_ == 0); |
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118 | return (last_ - first_) / stride_ + 1; |
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119 | } |
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120 | |
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121 | int stride() const |
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122 | { return stride_; } |
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123 | |
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124 | bool isAscendingContiguous() const |
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125 | { |
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126 | return ((first_ < last_) && (stride_ == 1) || (first_ == last_)); |
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127 | } |
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128 | |
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129 | void setRange(int first, int last, int stride=1) |
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130 | { |
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131 | BZPRECONDITION((first < last) && (stride > 0) || |
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132 | (first > last) && (stride < 0) || |
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133 | (first == last)); |
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134 | BZPRECONDITION((last-first) % stride == 0); |
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135 | first_ = first; |
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136 | last_ = last; |
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137 | stride_ = stride; |
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138 | } |
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139 | |
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140 | static Range all() |
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141 | { return Range(fromStart,toEnd,1); } |
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142 | |
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143 | bool isUnitStride() const |
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144 | { return stride_ == 1; } |
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145 | |
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146 | // Operators |
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147 | Range operator-(int shift) const |
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148 | { |
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149 | BZPRECONDITION(first_ != fromStart); |
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150 | BZPRECONDITION(last_ != toEnd); |
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151 | return Range(first_ - shift, last_ - shift, stride_); |
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152 | } |
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153 | |
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154 | Range operator+(int shift) const |
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155 | { |
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156 | BZPRECONDITION(first_ != fromStart); |
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157 | BZPRECONDITION(last_ != toEnd); |
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158 | return Range(first_ + shift, last_ + shift, stride_); |
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159 | } |
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160 | |
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161 | int operator[](unsigned i) const |
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162 | { |
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163 | return first_ + i * stride_; |
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164 | } |
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165 | |
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166 | int operator()(unsigned i) const |
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167 | { |
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168 | return first_ + i * stride_; |
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169 | } |
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170 | |
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171 | friend inline ostream& operator<<(ostream& os, const Range& range) |
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172 | { |
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173 | os << "Range(" << range.first() << "," << range.last() << "," |
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174 | << range.stride() << ")"; |
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175 | |
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176 | return os; |
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177 | } |
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178 | |
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179 | ///////////////////////////////////////////// |
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180 | // Library-internal member functions |
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181 | // These are undocumented and may change or |
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182 | // disappear in future releases. |
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183 | ///////////////////////////////////////////// |
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184 | |
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185 | static const int |
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186 | _bz_staticLengthCount = 0, |
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187 | _bz_dynamicLengthCount = 0, |
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188 | _bz_staticLength = 0; |
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189 | |
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190 | bool _bz_hasFastAccess() const |
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191 | { return stride_ == 1; } |
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192 | |
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193 | T_numtype _bz_fastAccess(unsigned i) const |
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194 | { return first_ + i; } |
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195 | |
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196 | unsigned _bz_suggestLength() const |
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197 | { |
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198 | return length(); |
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199 | } |
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200 | |
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201 | _bz_VecExpr<Range> _bz_asVecExpr() const |
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202 | { return _bz_VecExpr<Range>(*this); } |
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203 | |
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204 | private: |
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205 | int first_, last_, stride_; |
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206 | }; |
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207 | |
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208 | BZ_NAMESPACE_END |
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209 | |
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210 | #endif // BZ_RANGE_H |
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