1 | /// <summary>
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2 | /// For explicit code manipulation and execution. May also be used as a general list data types.
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3 | /// This types must always be present, as the top level interpreter will push any code to be executed on the
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4 | /// CODE stack prior to execution. However, one may turn off all CODE instructions if code manipulation is not needed.
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5 | /// </summary>
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6 |
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7 | namespace HeuristicLab.Problems.ProgramSynthesis.Push.Expressions {
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8 | using System;
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9 | using System.Collections.Generic;
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10 | using System.Linq;
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11 | using Attributes;
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12 | using Interpreter;
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13 | using Stack;
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14 |
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15 | /// <summary>
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16 | /// Recursively invokes the interpreter on the program on top of the CODE stack. After evaluation the
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17 | /// CODE stack is popped; normally this pops the program that was just executed, but if the expression itself
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18 | /// manipulates the stack then this final pop may end up popping something else.
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19 | /// </summary>
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20 | [PushExpression(StackTypes.Code, "CODE.DO", StackTypes.Exec)]
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21 | public class CodeDoExpression : StatelessExpression {
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22 | public override bool Eval(IInternalPushInterpreter interpreter) {
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23 | // not enough arguments on stack
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24 | if (interpreter.CodeStack.Count == 0) return false;
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25 |
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26 | var codePopExpression = ExpressionTable.GetStatelessExpression<CodePopExpression>();
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27 | interpreter.ExecStack.Push(codePopExpression, interpreter.CodeStack.Top);
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28 |
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29 | return true;
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30 | }
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31 | }
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32 |
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33 | /// <summary>
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34 | /// Like CODE.DO but pops the stack before, rather than after, the recursive execution
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35 | /// </summary>
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36 | [PushExpression(StackTypes.Code, "CODE.DO*", StackTypes.Exec)]
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37 | public class CodeDoXExpression : StatelessExpression {
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38 | public override bool Eval(IInternalPushInterpreter interpreter) {
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39 | // not enough arguments on stack
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40 | if (interpreter.CodeStack.Count == 0) return false;
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41 |
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42 | var expression = interpreter.CodeStack.Pop();
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43 | interpreter.ExecStack.Push(expression);
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44 |
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45 | return true;
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46 | }
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47 | }
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48 |
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49 | /// <summary>
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50 | /// Does nothing.
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51 | /// </summary>
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52 | [PushExpression(StackTypes.Code, "CODE.NOOP")]
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53 | public class CodeNoopExpression : StatelessExpression {
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54 | public override bool Eval(IInternalPushInterpreter interpreter) {
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55 | return false;
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56 | }
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57 | }
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58 |
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59 | /// <summary>
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60 | /// Specifies that the next expression submitted for execution will instead be pushed literally onto the CODE stack.
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61 | /// This can be implemented by moving the top item on the EXEC stack onto the CODE stack.
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62 | /// </summary>
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63 | [PushExpression(StackTypes.Code, "CODE.QUOTE", StackTypes.Exec)]
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64 | public class CodeQuoteExpression : StatelessExpression {
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65 | public override bool Eval(IInternalPushInterpreter interpreter) {
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66 | // not enough arguments on stack
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67 | if (interpreter.ExecStack.Count == 0) return false;
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68 |
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69 | var expression = interpreter.ExecStack.Pop();
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70 | interpreter.CodeStack.Push(expression);
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71 |
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72 | return true;
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73 | }
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74 | }
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75 |
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76 | /// <summary>
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77 | /// If the top item of the BOOLEAN stack is TRUE this recursively executes the second item of the CODE stack;
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78 | /// otherwise it recursively executes the first item of the CODE stack. Either way both elements of the CODE stack
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79 | /// (and the BOOLEAN value upon which the decision was made) are popped.
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80 | /// </summary>
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81 | [PushExpression(StackTypes.Code, "CODE.IF", StackTypes.Exec | StackTypes.Boolean)]
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82 | public class CodeIfExpression : StatelessExpression {
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83 | public override bool Eval(IInternalPushInterpreter interpreter) {
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84 | // not enough arguments on stack
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85 | if (interpreter.BooleanStack.Count == 0 ||
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86 | interpreter.CodeStack.Count < 2)
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87 | return false;
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88 |
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89 | var condition = interpreter.BooleanStack.Pop();
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90 | var first = interpreter.CodeStack[1];
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91 | var second = interpreter.CodeStack.Top;
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92 |
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93 | interpreter.CodeStack.Remove(2);
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94 | interpreter.ExecStack.Push(condition ? first : second);
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95 |
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96 | return true;
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97 | }
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98 | }
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99 |
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100 | /// <summary>
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101 | /// Pushes the result of appending the top two pieces of code. If one of the pieces of code is a single instruction or
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102 | /// literal (that is, something not surrounded by parentheses) then it is surrounded by parentheses first.
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103 | /// </summary>
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104 | [PushExpression(StackTypes.Code, "CODE.APPEND")]
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105 | public class CodeAppendExpression : StatelessExpression {
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106 | public override bool Eval(IInternalPushInterpreter interpreter) {
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107 | if (interpreter.CodeStack.Count < 2) return false;
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108 |
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109 | var first = interpreter.CodeStack.Top;
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110 | var second = interpreter.CodeStack[1];
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111 |
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112 | PushProgram firstProgram = null;
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113 | PushProgram secondProgram = null;
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114 |
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115 | if (first.IsProgram) {
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116 | firstProgram = (PushProgram)first;
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117 |
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118 | if (firstProgram.Depth > interpreter.Configuration.MaxDepth) return false;
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119 |
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120 | if (second.IsProgram) {
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121 | secondProgram = (PushProgram)second;
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122 |
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123 | if (secondProgram.Depth > interpreter.Configuration.MaxDepth ||
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124 | firstProgram.Count + secondProgram.Count > interpreter.Configuration.MaxPointsInProgram)
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125 | return false;
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126 | } else if (firstProgram.Count + 1 > interpreter.Configuration.MaxPointsInProgram) return false;
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127 | } else if (second.IsProgram) {
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128 | secondProgram = (PushProgram)second;
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129 |
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130 | if (secondProgram.Depth > interpreter.Configuration.MaxDepth
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131 | || secondProgram.Count + 1 > interpreter.Configuration.MaxPointsInProgram) return false;
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132 | } else if (interpreter.Configuration.MaxPointsInProgram <= 2) {
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133 | return false;
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134 | }
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135 |
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136 | interpreter.CodeStack.Pop();
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137 |
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138 | PushProgram result;
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139 |
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140 | if (firstProgram != null) {
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141 | result = secondProgram != null
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142 | ? PushProgram.Merge(interpreter.PoolContainer.PushProgramPool, interpreter.PoolContainer.ExpressionListPool, secondProgram, firstProgram)
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143 | : PushProgram.Merge(interpreter.PoolContainer.PushProgramPool, interpreter.PoolContainer.ExpressionListPool, second, firstProgram);
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144 | } else if (secondProgram != null) {
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145 | result = PushProgram.Merge(interpreter.PoolContainer.PushProgramPool, interpreter.PoolContainer.ExpressionListPool, first, secondProgram);
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146 | } else {
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147 | var expressions = interpreter.PoolContainer.ExpressionListPool.Get();
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148 | expressions.Add(second);
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149 | expressions.Add(first);
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150 |
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151 | result = PushProgram.Create(interpreter.PoolContainer.PushProgramPool, expressions);
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152 | }
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153 |
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154 | interpreter.CodeStack.SetTop(result);
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155 |
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156 | return true;
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157 | }
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158 | }
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159 |
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160 | /// <summary>
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161 | /// Pushes TRUE onto the BOOLEAN stack if the top piece of code is a single instruction or a literal,
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162 | /// and FALSE otherwise (that is, if it is something surrounded by parentheses).
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163 | /// </summary>
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164 | [PushExpression(StackTypes.Code, "CODE.ATOM", StackTypes.Boolean)]
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165 | public class CodeAtomExpression : StatelessExpression {
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166 | public override bool Eval(IInternalPushInterpreter interpreter) {
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167 | if (interpreter.CodeStack.Count == 0) return false;
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168 |
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169 | var expression = interpreter.CodeStack.Pop();
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170 | var isExpandExpression = expression.IsProgram;
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171 |
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172 | interpreter.BooleanStack.Push(!isExpandExpression);
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173 | return true;
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174 | }
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175 | }
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176 |
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177 | /// <summary>
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178 | /// Pushes the first item of the list on top of the CODE stack. For example, if the top piece of code is "( A B )"
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179 | /// then this pushes "A" (after popping the argument). If the code on top of the stack is not a list then this has no
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180 | /// effect.
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181 | /// The name derives from the similar Lisp function; a more generic name would be "FIRST".
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182 | /// </summary>
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183 | [PushExpression(StackTypes.Code, "CODE.CAR")]
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184 | public class CodeCarExpression : StatelessExpression {
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185 | public override bool Eval(IInternalPushInterpreter interpreter) {
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186 | if (interpreter.CodeStack.Count == 0 ||
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187 | !interpreter.CodeStack.Top.IsProgram) return false;
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188 |
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189 | var expand = interpreter.CodeStack.Top as PushProgram;
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190 |
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191 | if (expand.IsEmpty) return false;
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192 | var first = expand.Expressions[expand.Expressions.Count - 1];
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193 |
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194 | interpreter.CodeStack.SetTop(first);
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195 | return true;
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196 | }
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197 | }
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198 |
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199 | /// <summary>
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200 | /// Pushes a version of the list from the top of the CODE stack without its first element.
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201 | /// For example, if the top piece of code is "( A B )" then this pushes "( B )" (after popping the argument).
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202 | /// If the code on top of the stack is not a list then this pushes the empty list ("( )"). The name derives from
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203 | /// the similar Lisp function; a more generic name would be "REST".
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204 | /// </summary>
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205 | [PushExpression(StackTypes.Code, "CODE.CDR")]
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206 | public class CodeCdrExpression : StatelessExpression {
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207 | public override bool Eval(IInternalPushInterpreter interpreter) {
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208 | if (interpreter.CodeStack.Count == 0) return false;
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209 |
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210 | PushProgram result;
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211 | var top = interpreter.CodeStack.Top;
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212 |
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213 | if (top.IsProgram) {
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214 | var program = (PushProgram)top;
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215 |
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216 | if (program.IsEmpty) return false;
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217 |
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218 | var expressions = program.CopyExpressions(interpreter.PoolContainer.ExpressionListPool);
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219 | expressions.RemoveAt(expressions.Count - 1);
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220 |
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221 | result = PushProgram.Create(interpreter.PoolContainer.PushProgramPool, expressions as IReadOnlyList<Expression>);
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222 | } else {
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223 | result = PushProgram.Empty;
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224 | }
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225 |
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226 | interpreter.CodeStack.SetTop(result);
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227 | return true;
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228 | }
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229 | }
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230 |
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231 | /// <summary>
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232 | /// Pushes the result of "consing" (in the Lisp sense) the second stack item onto the first stack item
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233 | /// (which is coerced to a list if necessary). For example, if the top piece of code is "( A B )" and the
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234 | /// second piece of code is "X" then this pushes "( X A B )" (after popping the argument).
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235 | /// </summary>
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236 | [PushExpression(StackTypes.Code, "CODE.CONS")]
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237 | public class CodeConsExpression : StatelessExpression {
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238 | public override bool Eval(IInternalPushInterpreter interpreter) {
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239 | if (interpreter.CodeStack.Count < 2 ||
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240 | (interpreter.CodeStack.Top.IsProgram &&
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241 | ((PushProgram)interpreter.CodeStack.Top).Expressions.Count + 1 > interpreter.Configuration.MaxPointsInProgram))
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242 | return false;
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243 |
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244 | var expressions = interpreter.PoolContainer.ExpressionListPool.Get();
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245 | var first = interpreter.CodeStack.Pop();
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246 |
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247 | if (first.IsProgram) {
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248 | expressions.AddRange(((PushProgram)first).Expressions);
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249 | } else {
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250 | expressions.Add(first);
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251 | }
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252 |
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253 | expressions.Add(interpreter.CodeStack.Top);
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254 | var result = PushProgram.Create(interpreter.PoolContainer.PushProgramPool, expressions);
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255 | interpreter.CodeStack.SetTop(result);
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256 |
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257 | return true;
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258 | }
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259 | }
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260 |
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261 | /// <summary>
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262 | /// Pushes the "container" of the second CODE stack item within the first CODE stack item onto the CODE stack.
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263 | /// If second item contains the first anywhere (i.e. in any nested list) then the container is the smallest sub-list
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264 | /// that contains but is not equal to the first instance. For example, if the top piece of code is "( B ( C ( A ) ) ( D
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265 | /// ( A ) ) )"
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266 | /// and the second piece of code is "( A )" then this pushes ( C ( A ) ). Pushes an empty list if there is no such
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267 | /// container.
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268 | /// </summary>
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269 | [PushExpression(StackTypes.Code, "CODE.CONTAINER")]
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270 | public class CodeContainerExpression : StatelessExpression {
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271 | public override bool Eval(IInternalPushInterpreter interpreter) {
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272 | if ((interpreter.CodeStack.Count < 2) ||
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273 | (interpreter.CodeStack[1].GetType() !=
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274 | typeof(PushProgram))) return false;
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275 |
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276 | var target = interpreter.CodeStack.Pop();
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277 | var source = interpreter.CodeStack.Top;
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278 |
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279 | var container = GetContainer(source as PushProgram, target);
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280 | var result = container ?? PushProgram.Empty;
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281 |
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282 | interpreter.CodeStack.SetTop(result);
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283 | return true;
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284 | }
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285 |
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286 | private static PushProgram GetContainer(PushProgram current, Expression target) {
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287 | if (current == target)
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288 | return null;
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289 |
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290 | var subContainer =
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291 | current.Expressions.Where(e => e.IsProgram)
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292 | .Select(e => GetContainer(e as PushProgram, target))
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293 | .Where(e => e != null);
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294 |
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295 | var execExpandExpressions = subContainer as IList<PushProgram> ?? subContainer.ToList();
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296 | return execExpandExpressions.Any()
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297 | ? execExpandExpressions.OrderBy(c => c.Expressions.Count).LastOrDefault()
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298 | : current.Expressions.Contains(target)
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299 | ? current
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300 | : null;
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301 | }
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302 | }
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303 |
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304 | /// <summary>
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305 | /// Pushes TRUE on the BOOLEAN stack if the second CODE stack item contains the first CODE stack
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306 | /// item anywhere (e.g. in a sub-list).
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307 | /// </summary>
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308 | [PushExpression(StackTypes.Code, "CODE.CONTAINS", StackTypes.Boolean)]
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309 | public class CodeContainsExpression : StatelessExpression {
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310 | public override bool Eval(IInternalPushInterpreter interpreter) {
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311 | if (interpreter.CodeStack.Count < 2 ||
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312 | !interpreter.CodeStack[1].IsProgram)
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313 | return false;
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314 |
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315 | var second = (PushProgram)interpreter.CodeStack[1];
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316 | var first = interpreter.CodeStack.Top;
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317 | interpreter.CodeStack.Remove(2);
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318 |
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319 | var contains = second.Expressions.Contains(first);
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320 | interpreter.BooleanStack.Push(contains);
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321 | return true;
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322 | }
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323 | }
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324 |
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325 | /// <summary>
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326 | /// Pushes the definition associated with the top NAME on the NAME stack (if any) onto the CODE stack.
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327 | /// This extracts the definition for inspection/manipulation, rather than for immediate execution (although it
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328 | /// may then be executed with a call to CODE.DO or a similar instruction).
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329 | /// </summary>
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330 | [PushExpression(StackTypes.Code, "CODE.DEFINITION", StackTypes.Name)]
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331 | public class CodeDefinitionExpression : StatelessExpression {
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332 | public override bool Eval(IInternalPushInterpreter interpreter) {
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333 | if ((interpreter.NameStack.Count == 0) ||
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334 | !interpreter.CustomExpressions.ContainsKey(interpreter.NameStack.Top)) return false;
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335 |
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336 | var name = interpreter.NameStack.Pop();
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337 | var definition = interpreter.CustomExpressions[name];
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338 |
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339 | interpreter.CodeStack.Push(definition);
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340 |
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341 | return true;
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342 | }
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343 | }
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344 |
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345 | /// <summary>
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346 | /// Pushes a measure of the discrepancy between the top two CODE stack items onto the INTEGER stack. This will be zero
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347 | /// if the top two items are equivalent, and will be higher the 'more different' the items are from one another. The calculation
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348 | /// is as follows:
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349 | /// <list types="bullet">
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350 | /// <item>
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351 | /// <description>
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352 | /// Construct a list of all of the unique items in both of the lists(where uniqueness is determined by equalp).
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353 | /// Sub-lists and atoms all count as items.
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354 | /// </description>
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355 | /// </item>
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356 | /// <item>
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357 | /// <description>Initialize the result to zero.</description>
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358 | /// </item>
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359 | /// <item>
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360 | /// <description>
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361 | /// For each unique item increment the result by the difference between the number of occurrences of the
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362 | /// item in the two pieces of code.
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363 | /// </description>
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364 | /// </item>
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365 | /// <item>
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366 | /// <description>Push the result.</description>
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367 | /// </item>
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368 | /// </list>
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369 | /// </summary>
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370 | [PushExpression(StackTypes.Code, "CODE.DISCREPANCY", StackTypes.Integer)]
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371 | public class CodeDiscrepancyExpression : StatelessExpression {
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372 | public override bool Eval(IInternalPushInterpreter interpreter) {
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373 | if (interpreter.CodeStack.Count < 2) return false;
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374 |
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375 | var second = interpreter.CodeStack[1];
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376 | var first = interpreter.CodeStack.Top;
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377 | interpreter.CodeStack.Remove(2);
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378 |
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379 | var firstItems = new Dictionary<int, int>();
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380 | var secondItems = new Dictionary<int, int>();
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381 |
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382 | DetermineUniqueItems(second, secondItems);
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383 | DetermineUniqueItems(first, firstItems);
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384 |
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385 | var discrepancy = GetDiscrepancy(firstItems, secondItems);
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386 | interpreter.IntegerStack.Push(discrepancy);
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387 |
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388 | return true;
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389 | }
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390 |
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391 | private int GetDiscrepancy(IDictionary<int, int> first, IDictionary<int, int> second) {
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392 | var discrepancy = 0;
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393 | var keys = first.Keys.Concat(second.Keys).Distinct();
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394 |
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395 | foreach (var key in keys)
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396 | if (first.ContainsKey(key) && second.ContainsKey(key))
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397 | discrepancy += Math.Abs(first[key] - second[key]);
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398 | else if (first.ContainsKey(key)) discrepancy += first[key];
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399 | else discrepancy += second[key];
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400 |
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401 | return discrepancy;
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402 | }
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403 |
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404 | private void DetermineUniqueItems(Expression source, IDictionary<int, int> items) {
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405 | if (source.IsProgram) {
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406 | var program = source as PushProgram;
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407 | var expressions = program.Expressions;
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408 |
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409 | for (var i = 0; i < expressions.Count; i++) {
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410 | var id = expressions[i].GetHashCode();
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411 | if (!items.ContainsKey(id)) items.Add(id, 1);
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412 | else items[id]++;
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413 | }
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414 | } else {
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415 | items.Add(source.GetHashCode(), 1);
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416 | }
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417 | }
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418 | }
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419 |
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420 | /// <summary>
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421 | /// Pushes the sub-expression of the top item of the CODE stack that is indexed by the top item of the INTEGER stack.
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422 | /// The indexing here counts "points," where each parenthesized expression and each literal/instruction is considered a
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423 | /// point,
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424 | /// and it proceeds in depth first order. The entire piece of code is at index 0; if it is a list then the first item
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425 | /// in the list
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426 | /// is at index 1, etc. The integer used as the index is taken modulo the number of points in the overall expression
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427 | /// (and its
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428 | /// absolute value is taken in case it is negative) to ensure that it is within the meaningful range.
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429 | /// </summary>
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430 | [PushExpression(StackTypes.Code, "CODE.EXTRACT", StackTypes.Integer)]
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431 | public class CodeExtractExpression : StatelessExpression {
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432 | public override bool Eval(IInternalPushInterpreter interpreter) {
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433 | if (interpreter.IntegerStack.Count == 0 ||
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434 | interpreter.CodeStack.Count == 0 ||
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435 | !interpreter.CodeStack.Top.IsProgram)
|
---|
436 | return false;
|
---|
437 |
|
---|
438 | var expression = (PushProgram)interpreter.CodeStack.Top;
|
---|
439 | var index = (int)Math.Abs(interpreter.IntegerStack.Pop() % expression.TotalCount);
|
---|
440 | var result = expression.GetFromTree(index);
|
---|
441 |
|
---|
442 | interpreter.CodeStack.SetTop(result);
|
---|
443 |
|
---|
444 | return true;
|
---|
445 | }
|
---|
446 | }
|
---|
447 |
|
---|
448 | /// <summary>
|
---|
449 | /// Pops the BOOLEAN stack and pushes the popped item (TRUE or FALSE) onto the CODE stack.
|
---|
450 | /// </summary>
|
---|
451 | [PushExpression(StackTypes.Code, "CODE.FROMBOOLEAN", StackTypes.Boolean)]
|
---|
452 | public class CodeFromBooleanExpression : StatelessExpression {
|
---|
453 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
454 | if (interpreter.BooleanStack.Count == 0) return false;
|
---|
455 |
|
---|
456 | var value = interpreter.BooleanStack.Pop();
|
---|
457 | var expression = new BooleanPushExpression(value);
|
---|
458 |
|
---|
459 | interpreter.CodeStack.Push(expression);
|
---|
460 |
|
---|
461 | return true;
|
---|
462 | }
|
---|
463 | }
|
---|
464 |
|
---|
465 | /// <summary>
|
---|
466 | /// Pops the FLOAT stack and pushes the popped item onto the CODE stack.
|
---|
467 | /// </summary>
|
---|
468 | [PushExpression(StackTypes.Code, "CODE.FROMFLOAT", StackTypes.Float)]
|
---|
469 | public class CodeFromFloatExpression : StatelessExpression {
|
---|
470 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
471 | if (interpreter.FloatStack.Count == 0) return false;
|
---|
472 |
|
---|
473 | var value = interpreter.FloatStack.Pop();
|
---|
474 | var expression = new FloatPushExpression(value);
|
---|
475 |
|
---|
476 | interpreter.CodeStack.Push(expression);
|
---|
477 |
|
---|
478 | return true;
|
---|
479 | }
|
---|
480 | }
|
---|
481 |
|
---|
482 | /// <summary>
|
---|
483 | /// Pops the INTEGER stack and pushes the popped integer onto the CODE stack.
|
---|
484 | /// </summary>
|
---|
485 | [PushExpression(StackTypes.Code, "CODE.FROMINTEGER", StackTypes.Integer)]
|
---|
486 | public class CodeFromIntegerExpression : StatelessExpression {
|
---|
487 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
488 | if (interpreter.IntegerStack.Count == 0) return false;
|
---|
489 |
|
---|
490 | var value = interpreter.IntegerStack.Pop();
|
---|
491 | var expression = new IntegerPushExpression(value);
|
---|
492 |
|
---|
493 | interpreter.CodeStack.Push(expression);
|
---|
494 |
|
---|
495 | return true;
|
---|
496 | }
|
---|
497 | }
|
---|
498 |
|
---|
499 | /// <summary>
|
---|
500 | /// Pops the NAME stack and pushes the popped item onto the CODE stack.
|
---|
501 | /// </summary>
|
---|
502 | [PushExpression(StackTypes.Code, "CODE.FROMNAME", StackTypes.Name)]
|
---|
503 | public class CodeFromNameExpression : StatelessExpression {
|
---|
504 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
505 | if (interpreter.NameStack.Count == 0) return false;
|
---|
506 |
|
---|
507 | var value = interpreter.NameStack.Pop();
|
---|
508 | var expression = new NameDefineXExecExpression(value);
|
---|
509 |
|
---|
510 | interpreter.CodeStack.Push(expression);
|
---|
511 |
|
---|
512 | return true;
|
---|
513 | }
|
---|
514 | }
|
---|
515 |
|
---|
516 | /// <summary>
|
---|
517 | /// Pushes the result of inserting the second item of the CODE stack into the first item, at the position indexed
|
---|
518 | /// by the top item of the INTEGER stack (and replacing whatever was there formerly).
|
---|
519 | /// </summary>
|
---|
520 | [PushExpression(StackTypes.Code, "CODE.CODEINSERT", StackTypes.Integer)]
|
---|
521 | public class CodeInsertExpression : StatelessExpression {
|
---|
522 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
523 | if (interpreter.IntegerStack.Count == 0 ||
|
---|
524 | interpreter.CodeStack.Count < 2 ||
|
---|
525 | !interpreter.CodeStack.Top.IsProgram)
|
---|
526 | return false;
|
---|
527 |
|
---|
528 | var source = interpreter.CodeStack[1];
|
---|
529 | var target = (PushProgram)interpreter.CodeStack.Pop();
|
---|
530 | var index = (int)interpreter.IntegerStack.Pop();
|
---|
531 |
|
---|
532 | IList<Expression> newExpressions;
|
---|
533 | if (!target.IsEmpty) {
|
---|
534 | index = target.Expressions.Count - 1 - Math.Abs(index % target.Expressions.Count);
|
---|
535 | newExpressions = target.CopyExpressions(interpreter.PoolContainer.ExpressionListPool);
|
---|
536 |
|
---|
537 | newExpressions[index] = source.IsProgram
|
---|
538 | ? ((PushProgram)source).Copy(interpreter.PoolContainer.PushProgramPool)
|
---|
539 | : source;
|
---|
540 | } else {
|
---|
541 | newExpressions = interpreter.PoolContainer.ExpressionListPool.Get();
|
---|
542 | newExpressions.Add(source);
|
---|
543 | }
|
---|
544 |
|
---|
545 | var result = PushProgram.Create(interpreter.PoolContainer.PushProgramPool, newExpressions as IReadOnlyList<Expression>);
|
---|
546 | interpreter.CodeStack.SetTop(result);
|
---|
547 |
|
---|
548 | return true;
|
---|
549 | }
|
---|
550 | }
|
---|
551 |
|
---|
552 | /// <summary>
|
---|
553 | /// Pushes the length of the top item on the CODE stack onto the INTEGER stack.
|
---|
554 | /// If the top item is not a list then this pushes a 1. If the top item is a list then this pushes the
|
---|
555 | /// number of items in the top level of the list; that is, nested lists contribute only 1 to this count, no
|
---|
556 | /// matter what they contain.
|
---|
557 | /// </summary>
|
---|
558 | [PushExpression(StackTypes.Code, "CODE.LENGTH", StackTypes.Integer)]
|
---|
559 | public class CodeLengthExpression : StatelessExpression {
|
---|
560 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
561 | if (interpreter.CodeStack.Count == 0) return false;
|
---|
562 |
|
---|
563 | var expression = interpreter.CodeStack.Pop();
|
---|
564 | var count = 1;
|
---|
565 |
|
---|
566 | if (expression.IsProgram)
|
---|
567 | count = ((PushProgram)expression).Expressions.Count;
|
---|
568 |
|
---|
569 | interpreter.IntegerStack.Push(count);
|
---|
570 |
|
---|
571 | return true;
|
---|
572 | }
|
---|
573 | }
|
---|
574 |
|
---|
575 | /// <summary>
|
---|
576 | /// Pushes a list of the top two items of the CODE stack onto the CODE stack.
|
---|
577 | /// </summary>
|
---|
578 | [PushExpression(StackTypes.Code, "CODE.LIST")]
|
---|
579 | public class CodeListExpression : StatelessExpression {
|
---|
580 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
581 | if (interpreter.CodeStack.Count < 2 ||
|
---|
582 | (interpreter.CodeStack.Top.IsProgram && ((PushProgram)interpreter.CodeStack.Top).Depth == interpreter.Configuration.MaxDepth) ||
|
---|
583 | (interpreter.CodeStack[1].IsProgram && ((PushProgram)interpreter.CodeStack[1]).Depth == interpreter.Configuration.MaxDepth))
|
---|
584 | return false;
|
---|
585 |
|
---|
586 | var first = interpreter.CodeStack.Pop();
|
---|
587 | var second = interpreter.CodeStack.Top;
|
---|
588 |
|
---|
589 | var expressions = interpreter.PoolContainer.ExpressionListPool.Get();
|
---|
590 | expressions.Add(second);
|
---|
591 | expressions.Add(first);
|
---|
592 |
|
---|
593 | var expandExpression = PushProgram.Create(interpreter.PoolContainer.PushProgramPool, expressions);
|
---|
594 |
|
---|
595 | interpreter.CodeStack.SetTop(expandExpression);
|
---|
596 |
|
---|
597 | return true;
|
---|
598 | }
|
---|
599 | }
|
---|
600 |
|
---|
601 | /// <summary>
|
---|
602 | /// Pushes TRUE onto the BOOLEAN stack if the second item of the CODE stack is a member of the first item
|
---|
603 | /// (which is coerced to a list if necessary). Pushes FALSE onto the BOOLEAN stack otherwise.
|
---|
604 | /// </summary>
|
---|
605 | [PushExpression(StackTypes.Code, "CODE.MEMBER", StackTypes.Boolean)]
|
---|
606 | public class CodeMemberExpression : StatelessExpression {
|
---|
607 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
608 | if (interpreter.CodeStack.Count < 2) return false;
|
---|
609 |
|
---|
610 | var first = interpreter.CodeStack[1];
|
---|
611 | var second = interpreter.CodeStack.Top;
|
---|
612 | interpreter.CodeStack.Remove(2);
|
---|
613 |
|
---|
614 | var contains = second.IsProgram
|
---|
615 | ? ((PushProgram)second).Expressions.Contains(first)
|
---|
616 | : second.Equals(first);
|
---|
617 |
|
---|
618 | interpreter.BooleanStack.Push(contains);
|
---|
619 |
|
---|
620 | return true;
|
---|
621 | }
|
---|
622 | }
|
---|
623 |
|
---|
624 | /// <summary>
|
---|
625 | /// Pushes the nth element of the expression on top of the CODE stack (which is coerced to a list first if necessary).
|
---|
626 | /// If the expression is an empty list then the result is an empty list. N is taken from the INTEGER stack and is taken
|
---|
627 | /// modulo the length of the expression into which it is indexing.
|
---|
628 | /// </summary>
|
---|
629 | [PushExpression(StackTypes.Code, "CODE.NTH", StackTypes.Integer)]
|
---|
630 | public class CodeNthExpression : StatelessExpression {
|
---|
631 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
632 | if ((interpreter.CodeStack.Count == 0) || (interpreter.IntegerStack.Count == 0)) return false;
|
---|
633 |
|
---|
634 | var n = interpreter.IntegerStack.Pop();
|
---|
635 | var expression = interpreter.CodeStack.Top;
|
---|
636 |
|
---|
637 | Expression nthExpression;
|
---|
638 |
|
---|
639 | if (expression.IsProgram) {
|
---|
640 | var subExpression = (PushProgram)expression;
|
---|
641 |
|
---|
642 | if (subExpression.IsEmpty) {
|
---|
643 | nthExpression = PushProgram.Empty;
|
---|
644 | } else {
|
---|
645 | var index = (int)(subExpression.Expressions.Count - 1 - Math.Abs(n % subExpression.Expressions.Count));
|
---|
646 |
|
---|
647 | nthExpression = subExpression.Expressions[index];
|
---|
648 | }
|
---|
649 | } else {
|
---|
650 | nthExpression = expression;
|
---|
651 | }
|
---|
652 |
|
---|
653 | interpreter.CodeStack.SetTop(nthExpression);
|
---|
654 |
|
---|
655 | return true;
|
---|
656 | }
|
---|
657 | }
|
---|
658 |
|
---|
659 | /// <summary>
|
---|
660 | /// Pushes the nth "CDR" (in the Lisp sense) of the expression on top of the CODE stack (which is coerced to a list
|
---|
661 | /// first if necessary). If the expression is an empty list then the result is an empty list. N is taken from the
|
---|
662 | /// INTEGER
|
---|
663 | /// stack and is taken modulo the length of the expression into which it is indexing. A "CDR" of a list is the list
|
---|
664 | /// without
|
---|
665 | /// its first element.
|
---|
666 | /// </summary>
|
---|
667 | [PushExpression(StackTypes.Code, "CODE.NTHCDR", StackTypes.Integer)]
|
---|
668 | public class CodeNthCdrExpression : StatelessExpression {
|
---|
669 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
670 | if ((interpreter.CodeStack.Count == 0) || (interpreter.IntegerStack.Count == 0)) return false;
|
---|
671 |
|
---|
672 | var n = interpreter.IntegerStack.Pop();
|
---|
673 | var expression = interpreter.CodeStack.Top;
|
---|
674 |
|
---|
675 | Expression nthExpression;
|
---|
676 |
|
---|
677 | if (expression.IsProgram) {
|
---|
678 | var subExpressions = ((PushProgram)expression).Expressions;
|
---|
679 |
|
---|
680 | if (subExpressions.Count < 2) {
|
---|
681 | nthExpression = PushProgram.Empty;
|
---|
682 | } else {
|
---|
683 | var index = (int)(subExpressions.Count - 2 - Math.Abs(n % (subExpressions.Count - 1)));
|
---|
684 |
|
---|
685 | nthExpression = subExpressions[index];
|
---|
686 | }
|
---|
687 | } else {
|
---|
688 | nthExpression = expression;
|
---|
689 | }
|
---|
690 |
|
---|
691 | interpreter.CodeStack.SetTop(nthExpression);
|
---|
692 |
|
---|
693 | return true;
|
---|
694 | }
|
---|
695 | }
|
---|
696 |
|
---|
697 | /// <summary>
|
---|
698 | /// Pushes TRUE onto the BOOLEAN stack if the top item of the CODE stack is an empty list, or FALSE otherwise.
|
---|
699 | /// </summary>
|
---|
700 | [PushExpression(StackTypes.Code, "CODE.NULL", StackTypes.Boolean)]
|
---|
701 | public class CodeNullExpression : StatelessExpression {
|
---|
702 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
703 | if (interpreter.CodeStack.Count == 0) return false;
|
---|
704 |
|
---|
705 | var top = interpreter.CodeStack.Pop();
|
---|
706 | var result = top.IsProgram && ((PushProgram)top).IsEmpty;
|
---|
707 | interpreter.BooleanStack.Push(result);
|
---|
708 |
|
---|
709 | return true;
|
---|
710 | }
|
---|
711 | }
|
---|
712 |
|
---|
713 | /// <summary>
|
---|
714 | /// Pushes onto the INTEGER stack the position of the second item on the CODE stack within the first item
|
---|
715 | /// (which is coerced to a list if necessary). Pushes -1 if no match is found.
|
---|
716 | /// </summary>
|
---|
717 | [PushExpression(StackTypes.Code, "CODE.POSITION", StackTypes.Integer)]
|
---|
718 | public class CodePositionExpression : StatelessExpression {
|
---|
719 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
720 | if (interpreter.CodeStack.Count < 2) return false;
|
---|
721 |
|
---|
722 | var second = interpreter.CodeStack[1];
|
---|
723 | var first = interpreter.CodeStack.Top;
|
---|
724 | interpreter.CodeStack.Remove(2);
|
---|
725 |
|
---|
726 | var position = -1;
|
---|
727 | if (first.IsProgram) {
|
---|
728 | var program = (PushProgram)first;
|
---|
729 | position = program.IndexOf(second);
|
---|
730 | } else if (first.Equals(second)) {
|
---|
731 | position = 0;
|
---|
732 | }
|
---|
733 |
|
---|
734 | interpreter.IntegerStack.Push(position);
|
---|
735 |
|
---|
736 | return true;
|
---|
737 | }
|
---|
738 | }
|
---|
739 |
|
---|
740 | /// <summary>
|
---|
741 | /// Pushes the number of "points" in the top piece of CODE onto the INTEGER stack. Each instruction, literal,
|
---|
742 | /// and pair of parentheses counts as a point.
|
---|
743 | /// </summary>
|
---|
744 | [PushExpression(StackTypes.Code, "CODE.SIZE", StackTypes.Integer)]
|
---|
745 | public class CodeSizeExpression : StatelessExpression {
|
---|
746 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
747 | if (interpreter.CodeStack.Count == 0) return false;
|
---|
748 |
|
---|
749 | var expression = interpreter.CodeStack.Pop();
|
---|
750 | var points = expression.IsProgram
|
---|
751 | ? ((PushProgram)expression).Expressions.Count
|
---|
752 | : 1;
|
---|
753 |
|
---|
754 | interpreter.IntegerStack.Push(points);
|
---|
755 |
|
---|
756 | return true;
|
---|
757 | }
|
---|
758 | }
|
---|
759 |
|
---|
760 | /// <summary>
|
---|
761 | /// Pushes the result of substituting the third item on the code stack for the second item in the first item.
|
---|
762 | /// As of this writing this is implemented only in the Lisp implementation, within which it relies on the Lisp "subst"
|
---|
763 | /// function. As such, there are several problematic possibilities; for example "dotted-lists" can result in certain
|
---|
764 | /// cases with empty-list arguments. If any of these problematic possibilities occurs the stack is left unchanged.
|
---|
765 | /// </summary>
|
---|
766 | [PushExpression(StackTypes.Code, "CODE.SUBST")]
|
---|
767 | public class CodeSubstitutionExpression : StatelessExpression {
|
---|
768 | public override bool Eval(IInternalPushInterpreter interpreter) {
|
---|
769 | if ((interpreter.CodeStack.Count < 3) ||
|
---|
770 | (interpreter.CodeStack.Top.GetType() != typeof(PushProgram)))
|
---|
771 | return false;
|
---|
772 |
|
---|
773 | var third = interpreter.CodeStack[2];
|
---|
774 | var second = interpreter.CodeStack[1];
|
---|
775 | var first = interpreter.CodeStack.Top as PushProgram;
|
---|
776 | interpreter.CodeStack.Remove(2);
|
---|
777 |
|
---|
778 | var firstExpressions = first.Expressions;
|
---|
779 | var newExpressions = interpreter.PoolContainer.ExpressionListPool.Get();
|
---|
780 |
|
---|
781 | for (var i = 0; i < firstExpressions.Count; i++) {
|
---|
782 | var expression = firstExpressions[i].Equals(third)
|
---|
783 | ? second
|
---|
784 | /* no cloning needed here because first is removed and therefore newExpression is the only container of sub expressions */
|
---|
785 | : firstExpressions[i];
|
---|
786 |
|
---|
787 | newExpressions.Add(expression);
|
---|
788 | }
|
---|
789 |
|
---|
790 | var result = PushProgram.Create(interpreter.PoolContainer.PushProgramPool, newExpressions);
|
---|
791 |
|
---|
792 | interpreter.CodeStack.SetTop(result);
|
---|
793 |
|
---|
794 | return true;
|
---|
795 | }
|
---|
796 | }
|
---|
797 | } |
---|