1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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4 | * and the BEACON Center for the Study of Evolution in Action.
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5 | *
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6 | * This file is part of HeuristicLab.
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7 | *
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8 | * HeuristicLab is free software: you can redistribute it and/or modify
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9 | * it under the terms of the GNU General Public License as published by
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10 | * the Free Software Foundation, either version 3 of the License, or
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11 | * (at your option) any later version.
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12 | *
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13 | * HeuristicLab is distributed in the hope that it will be useful,
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14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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16 | * GNU General Public License for more details.
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17 | *
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18 | * You should have received a copy of the GNU General Public License
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19 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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20 | */
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21 | #endregion
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22 |
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23 | using System;
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24 | using System.Collections.Generic;
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25 | using System.IO;
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26 |
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27 | namespace HeuristicLab.Algorithms.DataAnalysis.MctsSymbolicRegression {
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28 | // this is the core class for generating expressions.
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29 | // the automaton determines which expressions are allowed
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30 | internal class Automaton {
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31 | public const int StateExpr = 1;
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32 | public const int StateExprEnd = 2;
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33 | public const int StateTermStart = 3;
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34 | public const int StateTermEnd = 4;
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35 | public const int StateFactorStart = 5;
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36 | public const int StateFactorEnd = 6;
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37 | public const int StateVariableFactorStart = 7;
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38 | public const int StateVariableFactorEnd = 8;
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39 | public const int StateExpFactorStart = 9;
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40 | public const int StateExpFactorEnd = 10;
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41 | public const int StateLogFactorStart = 11;
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42 | public const int StateLogFactorEnd = 12;
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43 | public const int StateInvFactorStart = 13;
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44 | public const int StateInvFactorEnd = 14;
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45 | public const int StateExpFStart = 15;
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46 | public const int StateExpFEnd = 16;
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47 | public const int StateLogTStart = 17;
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48 | public const int StateLogTEnd = 18;
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49 | public const int StateLogTFStart = 19;
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50 | public const int StateLogTFEnd = 20;
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51 | public const int StateInvTStart = 21;
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52 | public const int StateInvTEnd = 22;
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53 | public const int StateInvTFStart = 23;
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54 | public const int StateInvTFEnd = 24;
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55 | private const int FirstDynamicState = 25;
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56 |
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57 | private const int StartState = StateExpr;
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58 | public int CurrentState { get; private set; }
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59 |
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60 | public readonly List<string> stateNames;
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61 | private List<int>[] followStates;
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62 | private List<Action>[,] actions; // not every follow state is possible but this representation should be efficient
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63 | private List<string>[,] actionStrings; // just for printing
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64 | private readonly CodeGenerator codeGenerator;
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65 | private readonly ConstraintHandler constraintHandler;
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66 |
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67 | public Automaton(double[][] vars, int maxVarsInExpression = 100,
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68 | bool allowProdOfVars = true,
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69 | bool allowExp = true,
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70 | bool allowLog = true,
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71 | bool allowInv = true,
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72 | bool allowMultipleTerms = false) {
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73 | int nVars = vars.Length;
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74 | stateNames = new List<string>() { string.Empty, "Expr", "ExprEnd", "TermStart", "TermEnd", "FactorStart", "FactorEnd", "VarFactorStart", "VarFactorEnd", "ExpFactorStart", "ExpFactorEnd", "LogFactorStart", "LogFactorEnd", "InvFactorStart", "InvFactorEnd", "ExpFStart", "ExpFEnd", "LogTStart", "LogTEnd", "LogTFStart", "LogTFEnd", "InvTStart", "InvTEnd", "InvTFStart", "InvTFEnd" };
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75 | codeGenerator = new CodeGenerator();
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76 | constraintHandler = new ConstraintHandler(maxVarsInExpression);
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77 | BuildAutomaton(nVars, allowProdOfVars, allowExp, allowLog, allowInv, allowMultipleTerms);
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78 |
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79 | Reset();
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80 | #if DEBUG
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81 | PrintAutomaton();
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82 | #endif
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83 | }
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84 |
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85 | // reverse notation ops
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86 | // Expr -> c 0 Term { '+' Term } '+' '*' c '+' 'exit'
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87 | // Term -> c Fact { '*' Fact } '*'
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88 | // Fact -> VarFact | ExpFact | LogFact | InvFact
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89 | // VarFact -> var_1 ... var_n
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90 | // ExpFact -> 1 ExpF { '*' ExpF } '*' c '*' 'exp' // c must be at end to allow scaling in evaluator
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91 | // ExpF -> var_1 ... var_n
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92 | // LogFact -> 0 LogT { '+' LogT } '+' c '+' 'log' // c must be at end to allow scaling in evaluator
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93 | // LogT -> c LogTF { '*' LogTF } '*'
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94 | // LogTF -> var_1 ... var_n
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95 | // InvFact -> 1 InvT { '+' InvT } '+' 'inv'
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96 | // InvT -> (var_1 ... var_n) c '*'
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97 | private void BuildAutomaton(int nVars,
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98 | bool allowProdOfVars = true,
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99 | bool allowExp = true,
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100 | bool allowLog = true,
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101 | bool allowInv = true,
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102 | bool allowMultipleTerms = false) {
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103 |
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104 | int nStates = FirstDynamicState + 4 * nVars;
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105 | followStates = new List<int>[nStates];
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106 | actions = new List<Action>[nStates, nStates];
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107 | actionStrings = new List<string>[nStates, nStates];
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108 |
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109 | // Expr -> c 0 Term { '+' Term } '+' '*' c '+' 'exit'
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110 | AddTransition(StateExpr, StateTermStart, () => {
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111 | codeGenerator.Reset();
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112 | codeGenerator.Emit1(OpCodes.LoadParamN);
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113 | codeGenerator.Emit1(OpCodes.LoadConst0);
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114 | constraintHandler.Reset();
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115 | }, "c 0, Reset");
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116 | AddTransition(StateTermEnd, StateExprEnd, () => {
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117 | codeGenerator.Emit1(OpCodes.Add);
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118 | codeGenerator.Emit1(OpCodes.Mul);
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119 | codeGenerator.Emit1(OpCodes.LoadParamN);
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120 | codeGenerator.Emit1(OpCodes.Add);
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121 | codeGenerator.Emit1(OpCodes.Exit);
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122 | }, "+*c+ exit");
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123 | if (allowMultipleTerms)
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124 | AddTransition(StateTermEnd, StateTermStart, () => {
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125 | codeGenerator.Emit1(OpCodes.Add);
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126 | }, "+");
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127 |
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128 | // Term -> c Fact { '*' Fact } '*'
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129 | AddTransition(StateTermStart, StateFactorStart,
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130 | () => {
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131 | codeGenerator.Emit1(OpCodes.LoadParamN);
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132 | constraintHandler.StartTerm();
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133 | },
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134 | "c, StartTerm");
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135 | AddTransition(StateFactorEnd, StateTermEnd,
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136 | () => {
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137 | codeGenerator.Emit1(OpCodes.Mul);
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138 | constraintHandler.EndTerm();
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139 | },
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140 | "*, EndTerm");
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141 |
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142 | AddTransition(StateFactorEnd, StateFactorStart,
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143 | () => { codeGenerator.Emit1(OpCodes.Mul); },
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144 | "*");
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145 |
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146 |
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147 | // Fact -> VarFact | ExpFact | LogFact | InvFact
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148 | if (allowProdOfVars)
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149 | AddTransition(StateFactorStart, StateVariableFactorStart, () => {
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150 | constraintHandler.StartFactor(StateVariableFactorStart);
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151 | }, "StartFactor");
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152 | if (allowExp)
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153 | AddTransition(StateFactorStart, StateExpFactorStart, () => {
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154 | constraintHandler.StartFactor(StateExpFactorStart);
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155 | }, "StartFactor");
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156 | if (allowLog)
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157 | AddTransition(StateFactorStart, StateLogFactorStart, () => {
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158 | constraintHandler.StartFactor(StateLogFactorStart);
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159 | }, "StartFactor");
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160 | if (allowInv)
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161 | AddTransition(StateFactorStart, StateInvFactorStart, () => {
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162 | constraintHandler.StartFactor(StateInvFactorStart);
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163 | }, "StartFactor");
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164 | AddTransition(StateVariableFactorEnd, StateFactorEnd, () => { constraintHandler.EndFactor(); }, "EndFactor");
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165 | AddTransition(StateExpFactorEnd, StateFactorEnd, () => { constraintHandler.EndFactor(); }, "EndFactor");
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166 | AddTransition(StateLogFactorEnd, StateFactorEnd, () => { constraintHandler.EndFactor(); }, "EndFactor");
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167 | AddTransition(StateInvFactorEnd, StateFactorEnd, () => { constraintHandler.EndFactor(); }, "EndFactor");
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168 |
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169 | // VarFact -> var_1 ... var_n
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170 | // add dynamic states for each variable
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171 | int curDynVarState = FirstDynamicState;
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172 | for (int i = 0; i < nVars; i++) {
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173 | short varIdx = (short)i;
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174 | var varState = curDynVarState;
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175 | stateNames.Add("var_1");
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176 | AddTransition(StateVariableFactorStart, curDynVarState,
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177 | () => {
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178 | codeGenerator.Emit2(OpCodes.LoadVar, varIdx);
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179 | constraintHandler.AddVarToCurrentFactor(varState);
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180 | },
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181 | "var_" + varIdx + ", AddVar");
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182 | AddTransition(curDynVarState, StateVariableFactorEnd);
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183 | curDynVarState++;
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184 | }
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185 |
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186 | // ExpFact -> 1 ExpF { '*' ExpF } '*' c '*' 'exp'
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187 | AddTransition(StateExpFactorStart, StateExpFStart,
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188 | () => {
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189 | codeGenerator.Emit1(OpCodes.LoadConst1);
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190 | },
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191 | "1");
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192 | AddTransition(StateExpFEnd, StateExpFactorEnd,
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193 | () => {
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194 | codeGenerator.Emit1(OpCodes.Mul);
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195 | codeGenerator.Emit1(OpCodes.LoadParamN);
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196 | codeGenerator.Emit1(OpCodes.Mul);
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197 | codeGenerator.Emit1(OpCodes.Exp);
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198 | },
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199 | "*c*exp");
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200 | AddTransition(StateExpFEnd, StateExpFStart,
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201 | () => { codeGenerator.Emit1(OpCodes.Mul); },
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202 | "*");
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203 |
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204 | // ExpF -> var_1 ... var_n
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205 | for (int i = 0; i < nVars; i++) {
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206 | short varIdx = (short)i;
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207 | int varState = curDynVarState;
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208 | stateNames.Add("var_2");
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209 | AddTransition(StateExpFStart, curDynVarState,
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210 | () => {
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211 | codeGenerator.Emit2(OpCodes.LoadVar, varIdx);
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212 | constraintHandler.AddVarToCurrentFactor(varState);
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213 | },
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214 | "var_" + varIdx + ", AddVar");
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215 | AddTransition(curDynVarState, StateExpFEnd);
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216 | curDynVarState++;
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217 | }
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218 |
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219 | // must have c at end because of adjustment of c in evaluator
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220 | // LogFact -> 0 LogT { '+' LogT } '+' c '+' 'log'
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221 | AddTransition(StateLogFactorStart, StateLogTStart,
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222 | () => {
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223 | codeGenerator.Emit1(OpCodes.LoadConst0);
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224 | },
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225 | "0");
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226 | AddTransition(StateLogTEnd, StateLogFactorEnd,
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227 | () => {
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228 | codeGenerator.Emit1(OpCodes.Add);
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229 | codeGenerator.Emit1(OpCodes.LoadParamN);
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230 | codeGenerator.Emit1(OpCodes.Add);
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231 | codeGenerator.Emit1(OpCodes.Log);
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232 | },
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233 | "+c+log");
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234 | AddTransition(StateLogTEnd, StateLogTStart,
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235 | () => { codeGenerator.Emit1(OpCodes.Add); },
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236 | "+");
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237 |
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238 | // LogT -> c LogTF { '*' LogTF } '*'
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239 | AddTransition(StateLogTStart, StateLogTFStart,
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240 | () => {
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241 | codeGenerator.Emit1(OpCodes.LoadParamN);
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242 | },
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243 | "c");
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244 | AddTransition(StateLogTFEnd, StateLogTEnd,
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245 | () => {
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246 | codeGenerator.Emit1(OpCodes.Mul);
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247 | },
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248 | "*");
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249 | AddTransition(StateLogTFEnd, StateLogTFStart,
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250 | () => {
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251 | codeGenerator.Emit1(OpCodes.Mul);
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252 | },
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253 | "*");
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254 |
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255 | // LogTF -> var_1 ... var_n
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256 | for (int i = 0; i < nVars; i++) {
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257 | short varIdx = (short)i;
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258 | int varState = curDynVarState;
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259 | stateNames.Add("var_3");
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260 | AddTransition(StateLogTFStart, curDynVarState,
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261 | () => {
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262 | codeGenerator.Emit2(OpCodes.LoadVar, varIdx);
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263 | constraintHandler.AddVarToCurrentFactor(varState);
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264 | },
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265 | "var_" + varIdx + ", AddVar");
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266 | AddTransition(curDynVarState, StateLogTFEnd);
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267 | curDynVarState++;
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268 | }
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269 |
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270 | // InvFact -> 1 InvT { '+' InvT } '+' 'inv'
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271 | AddTransition(StateInvFactorStart, StateInvTStart,
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272 | () => {
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273 | codeGenerator.Emit1(OpCodes.LoadConst1);
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274 | },
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275 | "c");
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276 | AddTransition(StateInvTEnd, StateInvFactorEnd,
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277 | () => {
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278 | codeGenerator.Emit1(OpCodes.Add);
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279 | codeGenerator.Emit1(OpCodes.Inv);
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280 | },
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281 | "+inv");
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282 | AddTransition(StateInvTEnd, StateInvTStart,
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283 | () => { codeGenerator.Emit1(OpCodes.Add); },
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284 | "+");
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285 |
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286 | // InvT -> c InvTF { '*' InvTF } '*'
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287 | AddTransition(StateInvTStart, StateInvTFStart,
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288 | () => {
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289 | codeGenerator.Emit1(OpCodes.LoadParamN);
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290 | },
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291 | "c");
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292 | AddTransition(StateInvTFEnd, StateInvTEnd,
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293 | () => {
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294 | codeGenerator.Emit1(OpCodes.Mul);
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295 | },
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296 | "*");
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297 | AddTransition(StateInvTFEnd, StateInvTFStart,
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298 | () => {
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299 | codeGenerator.Emit1(OpCodes.Mul);
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300 | },
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301 | "*");
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302 |
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303 | // InvTF -> (var_1 ... var_n) c '*'
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304 | for (int i = 0; i < nVars; i++) {
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305 | short varIdx = (short)i;
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306 | int varState = curDynVarState;
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307 | stateNames.Add("var_4");
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308 | AddTransition(StateInvTFStart, curDynVarState,
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309 | () => {
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310 | codeGenerator.Emit2(OpCodes.LoadVar, varIdx);
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311 | constraintHandler.AddVarToCurrentFactor(varState);
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312 | },
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313 | "var_" + varIdx + ", AddVar");
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314 | AddTransition(curDynVarState, StateInvTFEnd);
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315 | curDynVarState++;
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316 | }
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317 |
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318 | followStates[StateExprEnd] = new List<int>(); // no follow states
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319 | }
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320 |
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321 | private void AddTransition(int fromState, int toState) {
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322 | if (followStates[fromState] == null) followStates[fromState] = new List<int>();
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323 | followStates[fromState].Add(toState);
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324 | }
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325 | private void AddTransition(int fromState, int toState, Action action, string str) {
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326 | if (followStates[fromState] == null) followStates[fromState] = new List<int>();
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327 | followStates[fromState].Add(toState);
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328 |
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329 | if (actions[fromState, toState] == null) {
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330 | actions[fromState, toState] = new List<Action>();
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331 | actionStrings[fromState, toState] = new List<string>();
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332 | }
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333 |
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334 | actions[fromState, toState].Add(action);
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335 | actionStrings[fromState, toState].Add(str);
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336 | }
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337 |
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338 | private readonly int[] followStatesBuf = new int[1000];
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339 | public void FollowStates(int state, out int[] buf, out int nElements) {
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340 | // return followStates[state]
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341 | // .Where(s => s < FirstDynamicState || s >= minVarIdx) // for variables we only allow non-decreasing state sequences
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342 | // // the following states imply an additional variable being added to the expression
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343 | // // F, Sum, Prod
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344 | // .Where(s => (s != StateF && s != StateSum && s != StateProd) || variablesRemaining > 0);
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345 |
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346 | // for loop instead of where iterator
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347 | var fs = followStates[state];
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348 | int j = 0;
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349 | //Console.Write(stateNames[CurrentState] + " allowed: ");
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350 | for (int i = 0; i < fs.Count; i++) {
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351 | var s = fs[i];
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352 | if (constraintHandler.IsAllowedFollowState(state, s)) {
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353 | //Console.Write(s + " ");
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354 | followStatesBuf[j++] = s;
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355 | }
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356 | }
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357 | //Console.WriteLine();
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358 | buf = followStatesBuf;
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359 | nElements = j;
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360 | }
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361 |
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362 |
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363 | public void Goto(int targetState) {
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364 | //Console.WriteLine("->{0}", stateNames[targetState]);
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365 | // Contract.Assert(FollowStates(CurrentState).Contains(targetState));
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366 |
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367 | if (actions[CurrentState, targetState] != null)
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368 | actions[CurrentState, targetState].ForEach(a => a()); // execute all actions
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369 | CurrentState = targetState;
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370 | }
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371 |
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372 | public bool IsFinalState(int s) {
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373 | return s == StateExprEnd;
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374 | }
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375 |
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376 | public void GetCode(out byte[] code, out int nParams) {
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377 | codeGenerator.GetCode(out code, out nParams);
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378 | }
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379 |
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380 | public void Reset() {
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381 | CurrentState = StartState;
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382 | codeGenerator.Reset();
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383 | constraintHandler.Reset();
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384 | }
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385 |
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386 | #if DEBUG
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387 | public void PrintAutomaton() {
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388 | using (var writer = new StreamWriter("automaton.gv")) {
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389 | writer.WriteLine("digraph {");
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390 | // writer.WriteLine("rankdir=LR");
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391 | int[] fs;
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392 | int nFs;
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393 | for (int s = StartState; s < stateNames.Count; s++) {
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394 | for (int i = 0; i < followStates[s].Count; i++) {
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395 | if (followStates[s][i] <= 0) continue;
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396 | var followS = followStates[s][i];
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397 | var label = actionStrings[s, followS] != null ? string.Join(" , ", actionStrings[s, followS]) : "";
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398 | writer.WriteLine("{0} -> {1} [ label = \"{2}\" ];", stateNames[s], stateNames[followS], label);
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399 | }
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400 | }
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401 | writer.WriteLine("}");
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402 | }
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403 | }
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404 | #endif
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405 | }
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406 | }
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