public PrologObject AdjustVariables(PrologObject po, ArrayList vars, int offset)
{
if (po is StructureObject)
{
po = ((StructureObject)po).Normalize();
}
if (po is StringObject && ((StringObject)po).IsVariableName())
{
int off;
off = vars.IndexOf(po);
if (off >= 0)
{
return(GetVariable(off + offset));
}
vars.Add(po);
po = GetVariable(offset + vars.Count - 1);
}
else if (po is StructureObject)
{
po = new StructureObject((StructureObject)po, this, vars, offset);
}
return(po);
}
private void Add(PrologMachine pm, PrologObject po)
{
if (po is StructureObject && ((StructureObject)(po)).Functor == this)
{
StructureObject ast = ((StructureObject)(po));
Add(pm, ast.Parameters[1]);
Add(pm, ast.Parameters[0]);
}
else
{
pm.PushPending(po);
}
}
private bool IsPredicate(PrologObject fact, StringObject atom)
{
if (fact.Equals(atom))
{
return(true);
}
if (!(fact is StructureObject))
{
return(false);
}
StructureObject st = ((StructureObject)(fact));
if (st.Functor.Equals(atom))
{
return(true);
}
if (!(st.Functor == IfPrimitive.GetInstance()))
{
return(false);
}
fact = st.Parameters[0];
if (fact.Equals(atom))
{
return(true);
}
if (!(fact is StructureObject))
{
return(false);
}
st = (StructureObject)fact;
if (st.Functor.Equals(atom))
{
return(true);
}
return(false);
}
public StructureObject(StructureObject st, PrologMachine pm, ArrayList vars, int offset)
{
this.functor = pm.AdjustVariables(st.Functor, vars, offset);
if (st.Arity == 0)
{
this.parameters = null;
}
else
{
this.parameters = new PrologObject[st.Arity];
}
for (int np = 0; np <= st.Arity - 1; np++)
{
this.parameters[np] = pm.AdjustVariables(st.Parameters[np], vars, offset);
}
}
public override bool Equals(object obj)
{
PrologObject objMe;
objMe = Normalize();
if (!(objMe == this))
{
return(objMe.Equals(obj));
}
if (obj is StructureObject)
{
obj = ((StructureObject)(obj)).Normalize();
}
if (obj == null || !(obj.GetType().Equals(this.GetType())))
{
return(false);
}
StructureObject st = ((StructureObject)(obj));
if (!(Functor.Equals(st.Functor)))
{
return(false);
}
if (!(Arity == st.Arity))
{
return(false);
}
for (int k = 0; k <= Arity - 1; k++)
{
if (!(Parameters[k].Equals(st.Parameters[k])))
{
return(false);
}
}
return(true);
}
public bool Unify(PrologObject po1, PrologObject po2)
{
po1 = po1.Dereference();
po2 = po2.Dereference();
if (po1.Equals(po2))
{
return(true);
}
if (po1 is Variable)
{
((Variable)(po1)).Bind(po2);
return(true);
}
if (po2 is Variable)
{
((Variable)(po2)).Bind(po1);
return(true);
}
if (po1 is StructureObject && po2 is StructureObject)
{
StructureObject st1 = ((StructureObject)(po1));
StructureObject st2 = ((StructureObject)(po2));
if (!(Unify(st1.Functor, st2.Functor)))
{
return(false);
}
if (!(st1.Arity == st2.Arity))
{
return(false);
}
for (int k = 0; k <= st1.Arity - 1; k++)
{
if (!(Unify(st1.Parameters[k], st2.Parameters[k])))
{
return(false);
}
}
return(true);
}
return(false);
}
public AndNode(PrologMachine pm, StructureObject st)
: base(pm, st)
{
}
public PrimitiveNode(PrologMachine pm, StructureObject st)
: base(pm, st)
{
primitive = ((Primitive)(st.Functor));
parameters = st.Parameters;
}
public PrimitiveStatusNode(PrologMachine pm, StructureObject st)
: base(pm, st)
{
}
public virtual PrologObject Evaluate(PrologMachine pm, StructureObject st)
{
return(st);
}