base/range.hh

   1 /*
   2  * Copyright (c) 2003 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef __RANGE_HH__
  30 #define __RANGE_HH__
  31
  32 #include <assert.h>
  33
  34 #include "base/intmath.hh"
  35 #include "base/str.hh"
  36
  37 template<class T>
  38 class Range
  39 {
  40   private:
  41     bool valid;
  42
  43   public:
  44     T start;
  45     T end;
  46
  47   public:
  48     Range() {}
  49
  50     Range(const Range &r) { operator=(r); }
  51
  52     Range(const T& s, const T& e)
  53         : start(s), end(e)
  54     {
  55         valid = (start <= end);
  56     }
  57
  58     Range(const std::string &s) { valid = parse(s); }
  59
  60     ~Range() {}
  61
  62     int compare(const T &p);
  63     bool parse(const std::string &s);
  64     const Range &operator=(const Range &r);
  65
  66     bool isValid() const { return valid; }
  67 };
  68
  69
  70 template<class T>
  71 inline int
  72 Range<T>::compare(const T &p)
  73 {
  74     assert(isValid());
  75
  76     if (p < start)
  77         return -1;
  78     else if (p > end)
  79         return 1;
  80     else
  81         return 0;
  82 }
  83
  84 // Parse a range string
  85 //
  86 // Ranges are in the following format:
  87 //    <range> := {<start_val>}:{<end>}
  88 //    <end>   := <end_val> | +<delta>
  89 template<class T>
  90 inline bool
  91 Range<T>::parse(const std::string &str)
  92 {
  93     std::vector<std::string> values;
  94     tokenize(values, str, ':');
  95
  96     T thestart, theend;
  97
  98     if (values.size() != 2)
  99         return false;
 100
 101     std::string s = values[0];
 102     std::string e = values[1];
 103
 104     if (!to_number(s, thestart))
 105         return false;
 106
 107     bool increment = (e[0] == '+');
 108     if (increment)
 109         e = e.substr(1);
 110
 111     if (!to_number(e, theend))
 112         return false;
 113
 114     if (increment)
 115         theend += thestart;
 116
 117     start = thestart;
 118     end = theend;
 119
 120     if (start > end)
 121         return false;
 122
 123     return true;
 124 }
 125
 126
 127 template<class T>
 128 inline const Range<T> &
 129 Range<T>::operator=(const Range<T> &r)
 130 {
 131     if (this != &r) {
 132         start = r.start;
 133         end = r.end;
 134
 135         valid = r.valid;
 136     }
 137     else {
 138         valid = false;
 139     }
 140
 141     return *this;
 142 }
 143
 144 template<class T>
 145 inline std::ostream &
 146 operator<<(std::ostream &o, const Range<T> &r)
 147 {
 148     // don't currently support output of invalid ranges
 149     assert(r.isValid());
 150     o << r.start << ":" << r.end;
 151     return o;
 152 }
 153
 154 //////////////////////////////////////////
 155 //
 156 // Compare two ranges
 157 //
 158 template<class T>
 159 inline bool
 160 operator==(const Range<T> &l, const Range<T> &r)
 161 {
 162     // ranges must both be valid to be equal
 163     return (l.isValid() && r.isValid() &&
 164             (l.start == r.start) && (l.end == r.end));
 165 }
 166
 167 template<class T>
 168 inline bool
 169 operator!=(const Range<T> &l, const Range<T> &r)
 170 {
 171     // for symmetry with ==, an invalid range is not equal to any other
 172     return (!l.isValid() || !r.isValid() ||
 173             (l.start != r.start) || (l.end != r.end));
 174 }
 175
 176 //////////////////////////////////////////
 177 //
 178 // Compare position to a range
 179 //
 180 // - 'pos == range' indicates that position pos is within the given range.
 181 //   This test always returns false if the range is invalid.
 182 //
 183 // - 'pos < range' and 'pos > range' indicate that the position is
 184 //   before the start of or after the end of the range, respectively.
 185 //   The range must be valid for these comparisons to be made.
 186 //
 187 // All other comparisons do the obvious thing based on these definitions.
 188 //
 189 //
 190
 191 //
 192 // Basic comparisons
 193 //
 194 template<class T>
 195 inline bool
 196 operator==(const T &pos, const Range<T> &range)
 197 {  return range.isValid() && pos >= range.start && pos <= range.end; }
 198
 199 template<class T>
 200 inline bool
 201 operator<(const T &pos, const Range<T> &range)
 202 {  assert(range.isValid()); return pos < range.start; }
 203
 204 template<class T>
 205 inline bool
 206 operator>(const T &pos, const Range<T> &range)
 207 {  assert(range.isValid()); return pos > range.end; }
 208
 209 //
 210 // Derived comparisons
 211 //
 212 template<class T>
 213 inline bool
 214 operator<=(const T &pos, const Range<T> &range)
 215 {  assert(range.isValid()); return pos <= range.end; }
 216
 217 template<class T>
 218 inline bool
 219 operator>=(const T &pos, const Range<T> &range)
 220 {  assert(range.isValid()); return pos >= range.start; }
 221
 222 template<class T>
 223 inline bool
 224 operator!=(const T &pos, const Range<T> &range)
 225 {  return !(pos == range); }
 226
 227 //
 228 // Define symmetric comparisons based on above
 229 //
 230 template<class T>
 231 inline bool
 232 operator>(const Range<T> &range, const T &pos)
 233 {  return pos < range; }
 234
 235 template<class T>
 236 inline bool
 237 operator<(const Range<T> &range, const T &pos)
 238 {  return pos > range; }
 239
 240 template<class T>
 241 inline bool
 242 operator<=(const Range<T> &range, const T &pos)
 243 {  return pos >= range; }
 244
 245 template<class T>
 246 inline bool
 247 operator>=(const Range<T> &range, const T &pos)
 248 {  return pos <= range; }
 249
 250 template<class T>
 251 inline bool
 252 operator==(const Range<T> &range, const T &pos)
 253 {  return (pos == range); }
 254
 255 template<class T>
 256 inline bool
 257 operator!=(const Range<T> &range, const T &pos)
 258 {  return (pos != range); }
 259
 260 #endif // __RANGE_HH__