|
private UnifyAndReturnCutState ( object v1, object v2 ) : IEnumerable |
||
| v1 | object | |
| v2 | object | |
| return | IEnumerable |
|
internal override IEnumerable <CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
if (args.Length != 1)
{
throw new ArgumentCountException("variable", args, new object[] { "Value" });
}
return(Term.UnifyAndReturnCutState(CurrentValue, args[0]));
}
private IEnumerable <CutState> BinaryPrimitiveImplementation(object[] args, PrologContext context)
{
if (args.Length != 2)
{
throw new ArgumentCountException(Name, args, expectedArguments);
}
var arg1 = Term.Deref(args[0]);
var arg2 = Term.Deref(args[1]);
var arg1AsLogicVariable = arg1 as LogicVariable;
if (arg1AsLogicVariable != null)
{
var arg2AsLogicVariable = arg2 as LogicVariable;
if (arg2AsLogicVariable != null)
{
// Enumerating both arguments
if (doubleEnumerator == null)
{
throw new InstantiationException(
arg1AsLogicVariable,
"At least one argument to " + Name + "/2 must be instantiated.");
}
if (arg1AsLogicVariable == arg2AsLogicVariable)
{
throw new InvalidOperationException(Name + "(X,X) is not supported.");
}
return(EnumerateBothDriver(arg1AsLogicVariable, arg2AsLogicVariable, context));
}
if (!(arg2 is T2))
{
throw new ArgumentTypeException(this.Name, this.arg2Name, arg1, typeof(T1));
}
if (arg1Function != null)
{
// It's left-unique
T1 arg1Value;
if (arg1Function((T2)arg2, out arg1Value))
{
return(Term.UnifyAndReturnCutState(arg1, arg1Value));
}
return(PrologPrimitives.FailImplementation);
}
// It's not left-unique
if (arg1Enumerator == null)
{
throw new InstantiationException(arg1AsLogicVariable, Name + "/2: first argument must be instantiated.");
}
return(this.EnumerateArg1Driver(arg1AsLogicVariable, (T2)arg2, context));
}
var variable1 = arg2 as LogicVariable;
if (variable1 != null)
{
if (!(arg1 is T1))
{
throw new ArgumentTypeException(this.Name, this.arg1Name, arg1, typeof(T1));
}
if (arg2Function != null)
{
// It's right-unique
T2 arg2Value;
if (arg2Function((T1)arg1, out arg2Value))
{
return(Term.UnifyAndReturnCutState(arg2, arg2Value));
}
return(PrologPrimitives.FailImplementation);
}
// It's not right-unqiue
if (arg2Enumerator == null)
{
throw new InstantiationException(variable1, Name + "/2: second argument must be instantiated.");
}
return(this.EnumerateArg2Driver((T1)arg1, variable1, context));
}
// Filtering
if (!(arg1 is T1))
{
throw new ArgumentTypeException(this.Name, this.arg1Name, arg1, typeof(T1));
}
if (!(arg2 is T2))
{
throw new ArgumentTypeException(this.Name, this.arg1Name, arg1, typeof(T1));
}
if (filter == null)
{
throw new InstantiatedVariableException(null, Name + ": at least one argument must be uninstantiated.");
}
return(CutStateSequencer.FromBoolean(this.filter((T1)arg1, (T2)arg2)));
}