public IEnumerable <bool> unify(object arg)
{
arg = YP.getValue(arg);
if (arg is Variable)
{
return(((Variable)arg).unify(this));
}
else
{
return(Equals(arg) ? YP.succeed() : YP.fail());
}
}
/// <summary>
/// If Obj is an Atom unify its _module with Module. If the Atom's _module is null, use Atom.NIL.
/// </summary>
/// <param name="Atom"></param>
/// <param name="Module"></param>
/// <returns></returns>
public static IEnumerable <bool> module(object Obj, object Module)
{
Obj = YP.getValue(Obj);
if (Obj is Atom)
{
if (((Atom)Obj)._module == null)
{
return(YP.unify(Module, Atom.NIL));
}
else
{
return(YP.unify(Module, ((Atom)Obj)._module));
}
}
return(YP.fail());
}
/// <summary>
/// If arg is another Functor, then succeed (yield once) if this and arg have the
/// same name and all functor args unify, otherwise fail (don't yield).
/// If arg is a Variable, then call its unify to unify with this.
/// Otherwise fail (don't yield).
/// </summary>
/// <param name="arg"></param>
/// <returns></returns>
public IEnumerable <bool> unify(object arg)
{
arg = YP.getValue(arg);
if (arg is Functor)
{
Functor argFunctor = (Functor)arg;
if (_name.Equals(argFunctor._name))
{
return(YP.unifyArrays(_args, argFunctor._args));
}
else
{
return(YP.fail());
}
}
else if (arg is Variable)
{
return(((Variable)arg).unify(this));
}
else
{
return(YP.fail());
}
}