mcs/class/Mono.CodeContracts/Mono.CodeContracts.Static.Analysis.Numerical/IntervalContext.cs

   1 //
   2 // IntervalContext.cs
   3 //
   4 // Authors:
   5 //      Alexander Chebaturkin (chebaturkin@gmail.com)
   6 //
   7 // Copyright (C) 2012 Alexander Chebaturkin
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using Mono.CodeContracts.Static.Lattices;
  30
  31 namespace Mono.CodeContracts.Static.Analysis.Numerical {
  32         class IntervalContext : IntervalRationalContextBase<Interval> {
  33                 public static readonly IntervalContext Instance = new IntervalContext ();
  34
  35                 IntervalContext ()
  36                 {
  37                 }
  38
  39                 public override Interval TopValue { get { return Interval.TopValue; } }
  40                 public override Interval BottomValue { get { return Interval.BottomValue; } }
  41
  42                 public override Interval Zero { get { return Interval.For (Rational.Zero); } }
  43                 public override Interval One { get { return Interval.For (Rational.One); } }
  44
  45                 public override Interval Positive { get { return Interval.For (0, Rational.PlusInfinity); } }
  46                 public override Interval Negative { get { return Interval.For (Rational.MinusInfinity, 0); } }
  47
  48                 public override Interval GreaterEqualThanMinusOne { get { return Interval.For (Rational.MinusOne, Rational.PlusInfinity); } }
  49
  50                 public override Interval For (long value)
  51                 {
  52                         return Interval.For (value);
  53                 }
  54
  55                 public override Interval For (long lower, long upper)
  56                 {
  57                         return Interval.For (lower, upper);
  58                 }
  59
  60                 public override Interval For (long lower, Rational upper)
  61                 {
  62                         return Interval.For (lower, upper);
  63                 }
  64
  65                 public override Interval For (Rational lower, long upper)
  66                 {
  67                         return Interval.For (lower, upper);
  68                 }
  69
  70                 public override Interval For (Rational value)
  71                 {
  72                         return Interval.For (value);
  73                 }
  74
  75                 public override Interval For (Rational lower, Rational upper)
  76                 {
  77                         return Interval.For (lower, upper);
  78                 }
  79
  80                 public override Interval LeftOpen (Rational upperBound)
  81                 {
  82                         return Interval.For (Rational.MinusInfinity, upperBound);
  83                 }
  84
  85                 public override Interval RightOpen (Rational lowerBound)
  86                 {
  87                         return Interval.For (lowerBound, Rational.PlusInfinity);
  88                 }
  89
  90                 public override Interval Add (Interval a, Interval b)
  91                 {
  92                         return a + b;
  93                 }
  94
  95                 public override Interval Sub (Interval a, Interval b)
  96                 {
  97                         return a - b;
  98                 }
  99
 100                 public override Interval Div (Interval a, Interval b)
 101                 {
 102                         return a / b;
 103                 }
 104
 105                 public override Interval Mul (Interval a, Interval b)
 106                 {
 107                         return a * b;
 108                 }
 109
 110                 public override Interval Not (Interval value)
 111                 {
 112                         if (!value.IsNormal ())
 113                                 return value;
 114
 115                         int intValue;
 116                         if (value.TryGetSingletonFiniteInt32 (out intValue))
 117                                 return Interval.For (intValue != 0 ? 0 : 1);
 118
 119                         return Interval.TopValue;
 120                 }
 121
 122                 public override Interval Rem (Interval a, Interval b)
 123                 {
 124                         return TopValue;
 125                 }
 126
 127                 public override Interval UnaryMinus (Interval value)
 128                 {
 129                         return -value;
 130                 }
 131
 132                 public override Interval ApplyConversion (ExpressionOperator conv, Interval intv)
 133                 {
 134                         return Interval.ApplyConversion (conv, intv);
 135                 }
 136         }
 137 }