protected override CodeTerm GetCodeTermBase(WamDeferenceTypes dereferenceType, WamReferenceTargetMapping mapping)
{
switch (dereferenceType)
{
case WamDeferenceTypes.AllVariables:
{
if (m_target == null)
{
return(new CodeValueObject(null));
}
return(m_target.GetCodeTerm(dereferenceType, mapping));
}
case WamDeferenceTypes.BoundVariables:
{
if (m_target == null)
{
return(mapping.Lookup(this));
}
return(m_target.GetCodeTerm(dereferenceType, mapping));
}
case WamDeferenceTypes.None:
{
return(mapping.Lookup(this));
}
default:
throw new InvalidOperationException(string.Format("Unknown dereferenceType {0}.", dereferenceType));
}
}
private PrologVariableList GetPermanentVariables(int stackIndex, bool getCodeTerm)
{
PrologVariableList result = new PrologVariableList();
WamEnvironment environment = WamMachine.GetEnvironment(stackIndex);
if (environment != null)
{
// Retrieve register name assignments from instruction stream.
//
Dictionary <int, string> variableNames;
WamInstructionStream wamInstructionStream = WamMachine.GetInstructionPointer(stackIndex).InstructionStream;
if (wamInstructionStream != null)
{
variableNames = wamInstructionStream.GetPermanentVariableAssignments();
}
else
{
variableNames = new Dictionary <int, string>();
}
for (int index = 0; index < environment.PermanentRegisters.Count; ++index)
{
PrologVariable variable = result.Add(string.Format("Y{0}", index));
string name;
if (variableNames.TryGetValue(index, out name))
{
variable.Name = name;
}
WamReferenceTarget referenceTarget = environment.PermanentRegisters[index];
if (referenceTarget != null)
{
if (getCodeTerm)
{
variable.CodeTerm = referenceTarget.GetCodeTerm();
}
else
{
variable.Text = referenceTarget.ToString();
}
}
}
}
return(result);
}
public static bool Assert(WamMachine machine, WamReferenceTarget[] arguments)
{
Debug.Assert(arguments.Length == 1);
WamReferenceTarget expression = machine.Evaluate(arguments[0]);
CodeTerm codeTerm = expression.GetCodeTerm();
if (codeTerm != null)
{
CodeValue codeValue = codeTerm as CodeValue;
if (codeValue != null)
{
return(Convert.ToBoolean(codeValue.Object));
}
}
return(false);
}