public override WamReferenceTarget Clone()
{
var result = new WamVariable(Generation);
if (Target != null)
{
result.Target = Target.Clone();
}
return result;
}
public override WamReferenceTarget Clone()
{
var result = new WamVariable(Generation);
if (Target != null)
{
result.Target = Target.Clone();
}
return(result);
}
void Trail(WamVariable variable)
{
if (ChoicePoint == null)
{
return;
}
if (variable.Generation <= ChoicePoint.Generation)
{
ChoicePoint.Trail.Add(variable);
}
}
public CodeVariable Lookup(WamVariable wamVariable)
{
if (wamVariable == null)
{
throw new ArgumentNullException("wamVariable");
}
CodeVariable codeVariable;
if (!_variables.TryGetValue(wamVariable, out codeVariable))
{
++_count;
codeVariable = new CodeVariable(string.Format("V{0}", _count));
_variables.Add(wamVariable, codeVariable);
}
return codeVariable;
}
public CodeVariable Lookup(WamVariable wamVariable)
{
if (wamVariable == null)
{
throw new ArgumentNullException("wamVariable");
}
CodeVariable codeVariable;
if (!_variables.TryGetValue(wamVariable, out codeVariable))
{
++_count;
codeVariable = new CodeVariable(string.Format("V{0}", _count));
_variables.Add(wamVariable, codeVariable);
}
return(codeVariable);
}
public static bool FindAll(WamMachine machine, WamReferenceTarget[] arguments)
{
Debug.Assert(arguments.Length == 3);
WamReferenceTarget arg0 = arguments[0].Dereference();
WamReferenceTarget arg1 = arguments[1].Dereference();
WamReferenceTarget arg2 = arguments[2].Dereference();
WamVariable variable = arg0 as WamVariable;
if (variable == null)
{
return(false);
}
WamCompoundTerm goal = arg1 as WamCompoundTerm;
if (goal == null)
{
return(false);
}
WamVariable result = arg2 as WamVariable;
if (result == null)
{
return(false);
}
WamInstructionStreamBuilder builder = new WamInstructionStreamBuilder();
builder.Write(new WamInstruction(WamInstructionOpCodes.Allocate));
for (int idx = 0; idx < goal.Functor.Arity; ++idx)
{
builder.Write(new WamInstruction(
WamInstructionOpCodes.PutValue,
goal.Children[idx],
new WamInstructionRegister(WamInstructionRegisterTypes.Argument, (byte)idx)));
}
builder.Write(new WamInstruction(WamInstructionOpCodes.Call, goal.Functor));
builder.Write(new WamInstruction(WamInstructionOpCodes.Success));
machine.PushContext(builder.ToInstructionStream());
List <WamReferenceTarget> values = new List <WamReferenceTarget>();
try
{
ExecutionResults results = machine.RunToSuccess();
while (results == ExecutionResults.Success)
{
WamReferenceTarget value = variable.Clone();
values.Add(value);
results = machine.RunToSuccess();
}
}
finally
{
machine.PopContext(true);
}
// Unbind the variable from the last results found by the goal.
//
variable.Unbind();
// Unify the output variable with the list of values.
//
return(machine.Unify(result, WamReferenceTarget.Create(values)));
}
private void Trail(WamVariable variable)
{
if (ChoicePoint != null)
{
if (variable.Generation <= ChoicePoint.Generation)
{
ChoicePoint.Trail.Add(variable);
}
}
}
private void Bind(WamVariable variable, WamReferenceTarget target)
{
variable.Bind(target);
Trail(variable);
}
void Bind(WamVariable variable, WamReferenceTarget target)
{
variable.Bind(target);
Trail(variable);
}
void Trail(WamVariable variable)
{
if (ChoicePoint == null) return;
if (variable.Generation <= ChoicePoint.Generation)
{
ChoicePoint.Trail.Add(variable);
}
}
