source: trunk/sources/HeuristicLab.Optimization/3.3/RunCollectionModification/Calculator.cs @ 7228

Last change on this file since 7228 was 7228, checked in by epitzer, 11 years ago

#1622: Move run collection modifiers into a separate folder

File size: 8.3 KB
Line 
1using System;
2using System.Collections.Generic;
3using System.Globalization;
4using System.Linq;
5using System.Text.RegularExpressions;
6using HeuristicLab.Common;
7using HeuristicLab.Core;
8using HeuristicLab.Data;
9using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
10using System.Text;
11
12namespace HeuristicLab.Optimization {
13
14  [StorableClass]
15  public class Calculator : IDeepCloneable {
16
17    #region Fields & Properties
18
19    private List<string> tokens;
20
21    [Storable]
22    public string Formula {
23      get { return string.Join(" ", tokens); }
24      set { tokens = Tokenize(value).ToList(); }
25    }
26
27    private static readonly Regex TokenRegex =
28      new Regex(@"""(\\""|[^""])*""|'(\\'|[^'])*'|[^\s]+");
29
30    #endregion
31
32    #region Construction & Cloning
33
34    [StorableConstructor]
35    protected Calculator(bool deserializing) { }
36    public Calculator() { }
37    protected Calculator(Calculator original, Cloner cloner) {
38      cloner.RegisterClonedObject(original, this);
39      if (original.tokens != null)
40        tokens = original.tokens.ToList();
41    }
42    public IDeepCloneable Clone(Cloner cloner) {
43      return new Calculator(this, cloner);
44    }
45    public object Clone() {
46      return Clone(new Cloner());
47    }
48    #endregion
49
50    private static IEnumerable<string> Tokenize(string s) {
51      return TokenRegex.Matches(s).Cast<Match>().Select(m => m.Value);
52    }
53
54    public IItem GetValue(IDictionary<string, IItem> variables) {
55      var stack = new Stack<object>();
56      int i = 0;
57      try {
58        for (; i<tokens.Count; i++) {
59          var token = tokens[i];
60          double d;
61          if (TryParse(token, out d)) {
62            stack.Push(d);
63          } else if (token.StartsWith("\"")) {
64            stack.Push(GetVariableValue(variables, token.Substring(1, token.Length - 2).Replace("\\\"", "\"")));
65          } else if (token.StartsWith("'")) {
66            stack.Push(token.Substring(1, token.Length-2).Replace("\\'", "'"));
67          } else {
68            Apply(token, stack, variables);
69          }
70        }
71      } catch (Exception x) {
72        throw new Exception(string.Format(
73          "Calculation of '{1}'{0}failed at token #{2}: {3} {0}current stack is: {0}{4}", Environment.NewLine,
74          Formula, i, TokenWithContext(tokens, i, 3),
75          string.Join(Environment.NewLine, stack.Select(AsString))),
76          x);
77      }
78      if (stack.Count != 1)
79        throw new Exception(
80          string.Format("Invalid final evaluation stack size {0} (should be 1) in formula '{1}'",
81          stack.Count, Formula));
82      var result = stack.Pop();
83      if (result is string) return new StringValue((string)result);
84      if (result is double) return new DoubleValue((double)result);
85      if (result is bool) return new BoolValue((bool)result);
86      return null;
87    }
88
89    private string TokenWithContext(List<string> tokens, int i, int context) {
90      var sb = new StringBuilder();
91      if (i > context+1)
92        sb.Append("... ");
93      int prefix = Math.Max(0, i - context);
94      sb.Append(string.Join(" ", tokens.GetRange(prefix, i - prefix)));
95      sb.Append("   ---> ").Append(tokens[i]).Append(" <---   ");
96      int postfix = Math.Min(tokens.Count, i + 1 + context);
97      sb.Append(string.Join(" ", tokens.GetRange(i + 1, postfix - (i + 1))));
98      if (postfix < tokens.Count)
99        sb.Append(" ...");
100      return sb.ToString();
101    }
102
103
104    private static void Apply(string token, Stack<object> stack, IDictionary<string, IItem> variables) {
105      switch (token) {
106        case "null":  stack.Push(null); break;
107        case "true":  stack.Push(true); break;
108        case "false": stack.Push(false); break;
109
110        case "drop": stack.Pop(); break;
111        case "dup": stack.Push(stack.Peek()); break;
112        case "swap":
113          var top = stack.Pop();
114          var next = stack.Pop();
115          stack.Push(top);
116          stack.Push(next);
117          break;
118
119        case "log": Apply(stack, x => Math.Log((double)x)); break;
120        case "+": Apply(stack, (x, y) => (double)x + (double)y); break;
121        case "-": Apply(stack, (x, y) => (double)x - (double)y); break;
122        case "*": Apply(stack, (x, y) => (double)x * (double)y); break;
123        case "/": Apply(stack, (x, y) => (double)x / (double)y); break;
124        case "^": Apply(stack, (x, y) => Math.Pow((double)x, (double)y)); break;
125        case "<": Apply(stack, (x, y) => (double)x < (double)y); break;
126        case ">": Apply(stack, (x, y) => (double)x > (double)y); break;
127
128        case "==": Apply(stack, (x, y) => Equal(x, y)); break;
129        case "not": Apply(stack, x => !(bool)x); break;
130        case "isnull": Apply(stack, x => x == null); break;
131        case "if": Apply(stack, (then, else_, cond) => (bool)cond ? then : else_); break;
132
133        case "ismatch": Apply(stack, (s, p) => new Regex((string)p).IsMatch((string)s)); break;
134        case "rename": Apply(stack, (s, p, r) => new Regex((string)p).Replace((string)s, (string)r)); break;
135
136        default: stack.Push(GetVariableValue(variables, token)); break;
137      }
138    }
139
140    #region Auxiliary Functions
141
142    #region IItem value conversion
143    private static object GetIntValue(IItem value) {
144      var v = value as IntValue;
145      if (v != null) return (double)v.Value;
146      return null;
147    }
148
149    private static object GetDoubleValue(IItem value) {
150      var v = value as DoubleValue;
151      if (v != null) return v.Value;
152      return null;
153    }
154
155    private static object GetBoolValue(IItem value) {
156      var v = value as BoolValue;
157      if (v != null) return v.Value;
158      return null;
159    }
160
161    private static object GetVariableValue(IDictionary<string, IItem> variables, string name) {
162      if (variables.ContainsKey(name)) {
163        var item = variables[name];
164        return
165          GetIntValue(item) ??
166          GetDoubleValue(item) ??
167          GetBoolValue(item) ??
168          item.ToString();
169      }
170      return null;
171    }
172    #endregion
173
174    #region variadic equality
175    private static bool Equal(object a, object b) { return EqualNumber(a, b) || EqualBool(a, b) || EqualString(a, b) || a == b; }
176    private static bool EqualNumber(object a, object b) { return a is double && b is double && (double)a == (double)b; }
177    private static bool EqualBool(object a, object b) { return a is bool && b is bool && (bool)a == (bool)b; }
178    private static bool EqualString(object a, object b) { return a is string && b is string && ((string)a).Equals((string)b); }
179    #endregion
180
181    #region stack calculation
182    private static void Apply(Stack<object> stack, Func<object, object> func) {
183      if (stack.Count < 1)
184        throw new InvalidOperationException("Stack is empty");
185      var a = stack.Pop();
186      try {
187        stack.Push(func(a));
188      } catch (Exception) {
189        stack.Push(a);
190        throw;
191      }
192    }
193
194    private static void Apply(Stack<object> stack, Func<object, object, object> func) {
195      if (stack.Count < 2)
196        throw new InvalidOperationException("Stack contains less than two elements");
197      var b = stack.Pop();
198      var a = stack.Pop();
199      try {
200        stack.Push(func(a, b));
201      } catch (Exception) {
202        stack.Push(b);
203        stack.Push(a);
204        throw;
205      }
206    }
207
208    private static void Apply(Stack<object> stack, Func<object, object, object, object> func) {
209      if (stack.Count < 3)
210        throw new InvalidOperationException("Stack contains less than three elements");
211      var c = stack.Pop();
212      var b = stack.Pop();
213      var a = stack.Pop();
214      try {
215        stack.Push(func(a, b, c));
216      } catch (Exception) {
217        stack.Push(a);
218        stack.Push(b);
219        stack.Push(c);
220        throw;
221      }
222    }
223    #endregion
224
225    private static bool TryParse(string token, out double d) {
226      return double.TryParse(token,
227                             NumberStyles.AllowDecimalPoint |
228                             NumberStyles.AllowExponent |
229                             NumberStyles.AllowLeadingSign, CultureInfo.InvariantCulture, out d);
230    }
231
232    private static string AsString(object o) {
233      if (o == null) return "null";
234      if (o is string) return string.Format("'{0}'", o);
235      return o.ToString();
236    }
237
238    #endregion
239  }
240}
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