Free cookie consent management tool by TermsFeed Policy Generator

source: branches/2931_OR-Tools_LP_MIP/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionCSharpFormatter.cs @ 16803

Last change on this file since 16803 was 16803, checked in by ddorfmei, 5 years ago

#2931: Merged revision(s) 16720-16802 from trunk

File size: 14.9 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2019 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using System;
23using System.Collections.Generic;
24using System.Globalization;
25using System.Linq;
26using System.Text;
27using System.Text.RegularExpressions;
28using HEAL.Attic;
29using HeuristicLab.Common;
30using HeuristicLab.Core;
31using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
32
33namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
34  [Item("C# Symbolic Expression Tree Formatter", "A string formatter that converts symbolic expression trees to C# code.")]
35  [StorableType("88298836-6087-405A-9354-D4E6864887EB")]
36  public sealed class CSharpSymbolicExpressionTreeStringFormatter : NamedItem, ISymbolicExpressionTreeStringFormatter {
37    [StorableConstructor]
38    private CSharpSymbolicExpressionTreeStringFormatter(StorableConstructorFlag _) : base(_) { }
39    private CSharpSymbolicExpressionTreeStringFormatter(CSharpSymbolicExpressionTreeStringFormatter original, Cloner cloner) : base(original, cloner) { }
40    public CSharpSymbolicExpressionTreeStringFormatter()
41      : base() {
42      Name = ItemName;
43      Description = ItemDescription;
44    }
45    public override IDeepCloneable Clone(Cloner cloner) {
46      return new CSharpSymbolicExpressionTreeStringFormatter(this, cloner);
47    }
48
49    public string Format(ISymbolicExpressionTree symbolicExpressionTree) {
50      // skip root and start symbols
51      StringBuilder strBuilder = new StringBuilder();
52      GenerateHeader(strBuilder, symbolicExpressionTree);
53      FormatRecursively(symbolicExpressionTree.Root.GetSubtree(0).GetSubtree(0), strBuilder);
54      GenerateFooter(strBuilder);
55      return strBuilder.ToString();
56    }
57
58    private string VariableName2Identifier(string name) {
59      /*
60       * identifier-start-character:
61       *    letter-character
62       *    _ (the underscore character U+005F)
63       *  identifier-part-characters:
64       *    identifier-part-character
65       *    identifier-part-characters   identifier-part-character
66       *  identifier-part-character:
67       *    letter-character
68       *    decimal-digit-character
69       *    connecting-character
70       *    combining-character
71       *    formatting-character
72       *  letter-character:
73       *    A Unicode character of classes Lu, Ll, Lt, Lm, Lo, or Nl
74       *    A unicode-escape-sequence representing a character of classes Lu, Ll, Lt, Lm, Lo, or Nl
75       *  combining-character:
76       *    A Unicode character of classes Mn or Mc
77       *    A unicode-escape-sequence representing a character of classes Mn or Mc
78       *  decimal-digit-character:
79       *    A Unicode character of the class Nd
80       *    A unicode-escape-sequence representing a character of the class Nd
81       *  connecting-character:
82       *    A Unicode character of the class Pc
83       *    A unicode-escape-sequence representing a character of the class Pc
84       *  formatting-character:
85       *    A Unicode character of the class Cf
86       *    A unicode-escape-sequence representing a character of the class Cf
87       */
88
89      var invalidIdentifierStarts = new Regex(@"[^_\p{Lu}\p{Ll}\p{Lt}\p{Lm}\p{Lo}\p{Nl}]");
90      var invalidIdentifierParts = new Regex(@"[^\p{Lu}\p{Ll}\p{Lt}\p{Lm}\p{Lo}\p{Nl}\p{Mn}\p{Mc}\p{Nd}\p{Pc}\p{Cf}]");
91      return "@" +
92        (invalidIdentifierStarts.IsMatch(name.Substring(0, 1)) ? "_" : "") + // prepend '_' if necessary
93        invalidIdentifierParts.Replace(name, "_");
94    }
95
96    private void FormatRecursively(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
97      // TODO: adapt to interpreter semantics. The HL interpreter also allows Boolean operations on reals
98      if (node.Subtrees.Any()) {
99        if (node.Symbol is Addition) {
100          FormatOperator(node, "+", strBuilder);
101        } else if (node.Symbol is And) {
102          FormatOperator(node, "&&", strBuilder);
103        } else if (node.Symbol is Average) {
104          FormatFunction(node, "Average", strBuilder);
105        } else if (node.Symbol is Cosine) {
106          FormatFunction(node, "Math.Cos", strBuilder);
107        } else if (node.Symbol is Division) {
108          FormatDivision(node, strBuilder);
109        } else if (node.Symbol is Exponential) {
110          FormatFunction(node, "Math.Exp", strBuilder);
111        } else if (node.Symbol is GreaterThan) {
112          FormatOperator(node, ">", strBuilder);
113        } else if (node.Symbol is IfThenElse) {
114          FormatFunction(node, "EvaluateIf", strBuilder);
115        } else if (node.Symbol is LessThan) {
116          FormatOperator(node, "<", strBuilder);
117        } else if (node.Symbol is Logarithm) {
118          FormatFunction(node, "Math.Log", strBuilder);
119        } else if (node.Symbol is Multiplication) {
120          FormatOperator(node, "*", strBuilder);
121        } else if (node.Symbol is Not) {
122          FormatOperator(node, "!", strBuilder);
123        } else if (node.Symbol is Or) {
124          FormatOperator(node, "||", strBuilder);
125        } else if (node.Symbol is Xor) {
126          FormatOperator(node, "^", strBuilder);
127        } else if (node.Symbol is Sine) {
128          FormatFunction(node, "Math.Sin", strBuilder);
129        } else if (node.Symbol is Subtraction) {
130          FormatSubtraction(node, strBuilder);
131        } else if (node.Symbol is Tangent) {
132          FormatFunction(node, "Math.Tan", strBuilder);
133        } else if (node.Symbol is HyperbolicTangent) {
134          FormatFunction(node, "Math.Tanh", strBuilder);
135        } else if (node.Symbol is Square) {
136          FormatSquare(node, strBuilder);
137        } else if (node.Symbol is SquareRoot) {
138          FormatFunction(node, "Math.Sqrt", strBuilder);
139        } else if (node.Symbol is Cube) {
140          FormatPower(node, strBuilder, "3");
141        } else if (node.Symbol is CubeRoot) {
142          FormatPower(node, strBuilder, "1.0/3");
143        } else if (node.Symbol is Power) {
144          FormatFunction(node, "Math.Pow", strBuilder);
145        } else if (node.Symbol is Root) {
146          FormatRoot(node, strBuilder);
147        } else if (node.Symbol is Absolute) {
148          FormatFunction(node, "Math.Abs", strBuilder);
149        } else if (node.Symbol is AnalyticQuotient) {
150          strBuilder.Append("(");
151          FormatRecursively(node.GetSubtree(0), strBuilder);
152          strBuilder.Append(" / Math.Sqrt(1 + Math.Pow(");
153          FormatRecursively(node.GetSubtree(1), strBuilder);
154          strBuilder.Append(" , 2) )");
155        } else {
156          throw new NotSupportedException("Formatting of symbol: " + node.Symbol + " not supported for C# symbolic expression tree formatter.");
157        }
158      } else {
159        if (node is VariableTreeNode) {
160          var varNode = node as VariableTreeNode;
161          strBuilder.AppendFormat("{0} * {1}", VariableName2Identifier(varNode.VariableName), varNode.Weight.ToString("g17", CultureInfo.InvariantCulture));
162        } else if (node is ConstantTreeNode) {
163          var constNode = node as ConstantTreeNode;
164          strBuilder.Append(constNode.Value.ToString("g17", CultureInfo.InvariantCulture));
165        } else if (node.Symbol is FactorVariable) {
166          var factorNode = node as FactorVariableTreeNode;
167          FormatFactor(factorNode, strBuilder);
168        } else if (node.Symbol is BinaryFactorVariable) {
169          var binFactorNode = node as BinaryFactorVariableTreeNode;
170          FormatBinaryFactor(binFactorNode, strBuilder);
171        } else {
172          throw new NotSupportedException("Formatting of symbol: " + node.Symbol + " not supported for C# symbolic expression tree formatter.");
173        }
174      }
175    }
176
177    private void FormatFactor(FactorVariableTreeNode node, StringBuilder strBuilder) {
178      strBuilder.AppendFormat("EvaluateFactor({0}, new [] {{ {1} }}, new [] {{ {2} }})", VariableName2Identifier(node.VariableName),
179        string.Join(",", node.Symbol.GetVariableValues(node.VariableName).Select(name => "\"" + name + "\"")), string.Join(",", node.Weights.Select(v => v.ToString(CultureInfo.InvariantCulture))));
180    }
181
182    private void FormatBinaryFactor(BinaryFactorVariableTreeNode node, StringBuilder strBuilder) {
183      strBuilder.AppendFormat(CultureInfo.InvariantCulture, "EvaluateBinaryFactor({0}, \"{1}\", {2})", VariableName2Identifier(node.VariableName), node.VariableValue, node.Weight);
184    }
185
186    private void FormatSquare(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
187      FormatPower(node, strBuilder, "2");
188    }
189    private void FormatPower(ISymbolicExpressionTreeNode node, StringBuilder strBuilder, string exponent) {
190      strBuilder.Append("Math.Pow(");
191      FormatRecursively(node.GetSubtree(0), strBuilder);
192      strBuilder.Append($", {exponent})");
193    }
194
195    private void FormatRoot(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
196      strBuilder.Append("Math.Pow(");
197      FormatRecursively(node.GetSubtree(0), strBuilder);
198      strBuilder.Append(", 1.0 / (");
199      FormatRecursively(node.GetSubtree(1), strBuilder);
200      strBuilder.Append("))");
201    }
202
203    private void FormatDivision(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
204      if (node.SubtreeCount == 1) {
205        strBuilder.Append("1.0 / ");
206        FormatRecursively(node.GetSubtree(0), strBuilder);
207      } else {
208        FormatRecursively(node.GetSubtree(0), strBuilder);
209        strBuilder.Append("/ (");
210        for (int i = 1; i < node.SubtreeCount; i++) {
211          if (i > 1) strBuilder.Append(" * ");
212          FormatRecursively(node.GetSubtree(i), strBuilder);
213        }
214        strBuilder.Append(")");
215      }
216    }
217
218    private void FormatSubtraction(ISymbolicExpressionTreeNode node, StringBuilder strBuilder) {
219      if (node.SubtreeCount == 1) {
220        strBuilder.Append("-");
221        FormatRecursively(node.GetSubtree(0), strBuilder);
222        return;
223      }
224      //Default case: more than 1 child
225      FormatOperator(node, "-", strBuilder);
226    }
227
228    private void FormatOperator(ISymbolicExpressionTreeNode node, string symbol, StringBuilder strBuilder) {
229      strBuilder.Append("(");
230      foreach (var child in node.Subtrees) {
231        FormatRecursively(child, strBuilder);
232        if (child != node.Subtrees.Last())
233          strBuilder.Append(" " + symbol + " ");
234      }
235      strBuilder.Append(")");
236    }
237
238    private void FormatFunction(ISymbolicExpressionTreeNode node, string function, StringBuilder strBuilder) {
239      strBuilder.Append(function + "(");
240      foreach (var child in node.Subtrees) {
241        FormatRecursively(child, strBuilder);
242        if (child != node.Subtrees.Last())
243          strBuilder.Append(", ");
244      }
245      strBuilder.Append(")");
246    }
247
248    private void GenerateHeader(StringBuilder strBuilder, ISymbolicExpressionTree symbolicExpressionTree) {
249      strBuilder.AppendLine("using System;");
250      strBuilder.AppendLine("using System.Linq;" + Environment.NewLine);
251      strBuilder.AppendLine("namespace HeuristicLab.Models {");
252      strBuilder.AppendLine("public static class Model {");
253      GenerateAverageSource(strBuilder);
254      GenerateIfThenElseSource(strBuilder);
255      GenerateFactorSource(strBuilder);
256      GenerateBinaryFactorSource(strBuilder);
257      strBuilder.Append(Environment.NewLine + "public static double Evaluate (");
258
259      // here we don't have access to problemData to determine the type for each variable (double/string) therefore we must distinguish based on the symbol type
260      HashSet<string> doubleVarNames = new HashSet<string>();
261      foreach (var node in symbolicExpressionTree.IterateNodesPostfix().Where(x => x is VariableTreeNode || x is VariableConditionTreeNode)) {
262        doubleVarNames.Add(((IVariableTreeNode)node).VariableName);
263      }
264
265      HashSet<string> stringVarNames = new HashSet<string>();
266      foreach (var node in symbolicExpressionTree.IterateNodesPostfix().Where(x => x is BinaryFactorVariableTreeNode || x is FactorVariableTreeNode)) {
267        stringVarNames.Add(((IVariableTreeNode)node).VariableName);
268      }
269
270      var orderedNames = stringVarNames.OrderBy(n => n, new NaturalStringComparer()).Select(n => "string " + VariableName2Identifier(n) + " /* " + n + " */");
271      strBuilder.Append(string.Join(", ", orderedNames));
272
273      if (stringVarNames.Any() && doubleVarNames.Any())
274        strBuilder.AppendLine(",");
275      orderedNames = doubleVarNames.OrderBy(n => n, new NaturalStringComparer()).Select(n => "double " + VariableName2Identifier(n) + " /* " + n + " */");
276      strBuilder.Append(string.Join(", ", orderedNames));
277
278
279      strBuilder.AppendLine(") {");
280      strBuilder.Append("double result = ");
281    }
282
283    private void GenerateFooter(StringBuilder strBuilder) {
284      strBuilder.AppendLine(";");
285
286      strBuilder.AppendLine("return result;");
287      strBuilder.AppendLine("}");
288      strBuilder.AppendLine("}");
289      strBuilder.AppendLine("}");
290    }
291
292    private void GenerateAverageSource(StringBuilder strBuilder) {
293      strBuilder.AppendLine("private static double Average(params double[] values) {");
294      strBuilder.AppendLine("  return values.Average();");
295      strBuilder.AppendLine("}");
296    }
297
298    private void GenerateIfThenElseSource(StringBuilder strBuilder) {
299      strBuilder.AppendLine("private static double EvaluateIf(bool condition, double then, double @else) {");
300      strBuilder.AppendLine("   return condition ? then : @else;");
301      strBuilder.AppendLine("}");
302    }
303
304    private void GenerateFactorSource(StringBuilder strBuilder) {
305      strBuilder.AppendLine("private static double EvaluateFactor(string factorValue, string[] factorValues, double[] constants) {");
306      strBuilder.AppendLine("   for(int i=0;i<factorValues.Length;i++) " +
307                            "      if(factorValues[i] == factorValue) return constants[i];" +
308                            "   throw new ArgumentException();");
309      strBuilder.AppendLine("}");
310    }
311
312    private void GenerateBinaryFactorSource(StringBuilder strBuilder) {
313      strBuilder.AppendLine("private static double EvaluateBinaryFactor(string factorValue, string targetValue, double weight) {");
314      strBuilder.AppendLine("  return factorValue == targetValue ? weight : 0.0;");
315      strBuilder.AppendLine("}");
316    }
317
318  }
319}
Note: See TracBrowser for help on using the repository browser.