protected static ISymbolicExpressionTreeNode GenerateAndInsertNewSubtree(IRandom random, ISymbolicExpressionTreeNode parent, List <ISymbol> allowedSymbols, int childIndex, int maxLength, int maxDepth)
{
var weights = allowedSymbols.Select(s => s.InitialFrequency).ToList();
#pragma warning disable 612, 618
var seedSymbol = allowedSymbols.SelectRandom(weights, random);
#pragma warning restore 612, 618
// replace the old node with the new node
var seedNode = seedSymbol.CreateTreeNode();
if (seedNode.HasLocalParameters)
{
seedNode.ResetLocalParameters(random);
}
parent.RemoveSubtree(childIndex);
parent.InsertSubtree(childIndex, seedNode);
ProbabilisticTreeCreator.PTC2(random, seedNode, maxLength, maxDepth);
return(seedNode);
}
public override void ReplaceBranch(IRandom random, ISymbolicExpressionTree symbolicExpressionTree, ICFGPythonProblemData problemData, ItemArray <PythonStatementSemantic> semantics, PythonProcess pythonProcess, double timeout, int maxTreeLength, int maxTreeDepth, int maximumSemanticTries)
{
if (semantics == null || semantics.Length == 0)
{
ReplaceBranchManipulation.ReplaceRandomBranch(random, symbolicExpressionTree, maxTreeLength, maxTreeDepth);
SemanticallyEquivalentMutationParameter.ActualValue = new IntValue(NoSemantics);
MutationTypeParameter.ActualValue = new IntValue(RandomMutation);
return;
}
var allowedSymbols = new List <ISymbol>();
ISymbolicExpressionTreeNode parent;
int childIndex;
int maxLength;
int maxDepth;
// repeat until a fitting parent and child are found (MAX_TRIES times)
int tries = 0;
ISymbolicExpressionTreeNode child;
do
{
#pragma warning disable 612, 618
parent = symbolicExpressionTree.Root.IterateNodesPrefix().Skip(1).Where(n => n.SubtreeCount > 0).SelectRandom(random);
#pragma warning restore 612, 618
childIndex = random.Next(parent.SubtreeCount);
child = parent.GetSubtree(childIndex);
maxLength = maxTreeLength - symbolicExpressionTree.Length + child.GetLength();
maxDepth = maxTreeDepth - symbolicExpressionTree.Root.GetBranchLevel(child);
allowedSymbols.Clear();
foreach (var symbol in parent.Grammar.GetAllowedChildSymbols(parent.Symbol, childIndex))
{
// check basic properties that the new symbol must have
if ((symbol.Name != child.Symbol.Name || symbol.MinimumArity > 0) &&
symbol.InitialFrequency > 0 &&
parent.Grammar.GetMinimumExpressionDepth(symbol) <= maxDepth &&
parent.Grammar.GetMinimumExpressionLength(symbol) <= maxLength)
{
allowedSymbols.Add(symbol);
}
}
tries++;
} while (tries < MAX_TRIES && allowedSymbols.Count == 0);
NumberOfTriesParameter.ActualValue = new IntValue(tries); //normal tries. not semantic tries
if (tries < MAX_TRIES)
{
var statementProductionNames = SemanticOperatorHelper.GetSemanticProductionNames(symbolicExpressionTree.Root.Grammar);
var variables = problemData.Variables.GetVariableNames().ToList();
#region calculate original json output
ISymbolicExpressionTreeNode statement = SemanticOperatorHelper.GetStatementNode(child, statementProductionNames);
string variableSettings = problemData.VariableSettings.Count == 0 ? String.Empty : String.Join(Environment.NewLine, problemData.VariableSettings.Select(x => x.Value));
var statementPos0 = symbolicExpressionTree.IterateNodesPrefix().ToList().IndexOf(statement);
if (String.IsNullOrEmpty(variableSettings))
{
variableSettings = SemanticOperatorHelper.SemanticToPythonVariableSettings(semantics.First(x => x.TreeNodePrefixPos == statementPos0).Before, problemData.Variables.GetVariableTypes());
}
var jsonOriginal = SemanticOperatorHelper.EvaluateStatementNode(statement, pythonProcess, random, problemData, variables, variableSettings, timeout);
#endregion
var weights = allowedSymbols.Select(s => s.InitialFrequency).ToList();
#pragma warning disable 612, 618
var seedSymbol = allowedSymbols.SelectRandom(weights, random);
#pragma warning restore 612, 618
// replace the old node with the new node
var seedNode = seedSymbol.CreateTreeNode();
if (seedNode.HasLocalParameters)
{
seedNode.ResetLocalParameters(random);
}
parent.RemoveSubtree(childIndex);
parent.InsertSubtree(childIndex, seedNode);
ProbabilisticTreeCreator.PTC2(random, seedNode, maxLength, maxDepth);
JObject jsonReplaced;
if (child == statement)
{
// child is executable, so is the new child
jsonReplaced = SemanticOperatorHelper.EvaluateStatementNode(seedNode, pythonProcess, random, problemData, variables, variableSettings, timeout);
}
else
{
jsonReplaced = SemanticOperatorHelper.EvaluateStatementNode(statement, pythonProcess, random, problemData, variables, variableSettings, timeout);
}
if (JToken.EqualityComparer.Equals(jsonOriginal, jsonReplaced))
{
SemanticallyEquivalentMutationParameter.ActualValue = new IntValue(Equvivalent);
}
else
{
SemanticallyEquivalentMutationParameter.ActualValue = new IntValue(Different);
}
MutationTypeParameter.ActualValue = new IntValue(RandomMutation);
}
else
{
SemanticallyEquivalentMutationParameter.ActualValue = new IntValue(NoMutation);
MutationTypeParameter.ActualValue = new IntValue(NoMutation);
}
}