public void PushContext(WamInstructionStream instructionStream)
{
if (instructionStream == null)
{
throw new ArgumentNullException("instructionStream");
}
var context = new WamContext();
_contextStack.Push(context);
CurrentContext = context;
State = WamMachineStates.Run;
InstructionPointer = new WamInstructionPointer(instructionStream);
ReturnInstructionPointer = WamInstructionPointer.Undefined;
StackIndex = 0;
Environment = null;
ChoicePoint = null;
ArgumentRegisters.Clear();
TemporaryRegisters.Clear();
CurrentStructure = null;
CurrentStructureIndex = -1;
}
private WamMachine(Program program, Query query)
{
if (program == null)
{
throw new ArgumentNullException("program");
}
if (query == null)
{
throw new ArgumentNullException("query");
}
m_program = program;
m_query = query;
m_contextStack = new Stack<WamContext>();
m_currentContext = null;
m_performanceStatistics = new PerformanceStatistics();
}
private void ClearContextStack()
{
m_contextStack.Clear();
m_currentContext = null;
}
public void PopContext(bool unwindTrail)
{
if (m_contextStack.Count == 0)
{
throw new InvalidOperationException("Context stack is empty.");
}
if (unwindTrail)
{
while (ChoicePoint != null)
{
UnwindTrail();
ChoicePoint = ChoicePoint.Predecessor;
}
}
m_contextStack.Pop();
if (m_contextStack.Count == 0)
{
m_currentContext = null;
}
else
{
m_currentContext = m_contextStack.Peek();
}
}
public void PushContext(WamInstructionStream instructionStream)
{
if (instructionStream == null)
{
throw new ArgumentNullException("instructionStream");
}
WamContext context = new WamContext();
m_contextStack.Push(context);
m_currentContext = context;
State = WamMachineStates.Run;
InstructionPointer = new WamInstructionPointer(instructionStream);
ReturnInstructionPointer = WamInstructionPointer.Undefined;
StackIndex = 0;
Environment = null;
ChoicePoint = null;
ArgumentRegisters.Clear();
TemporaryRegisters.Clear();
CurrentStructure = null;
CurrentStructureIndex = -1;
}