public IType Invoke(IType[] args)
{
if (args.Length != 2)
{
throw new RuntimeException("LDIFF: Exactly 2 arguments required");
}
if (!Array.TrueForAll(args, (IType x) => x is null || x is Cons))
{
throw new RuntimeException("LDIFF: Invalid Argument type");
}
if (args[0] is null)
{
return(null);
}
Cons c = args[0] as Cons;
if (c.Equals(args[1]))
{
return(null);
}
Cons ret = new Cons(c.car, Lisp.nil);
Cons cur = ret;
while (c.cdr is Cons d && !d.Equals(args[1]))
{
cur.cdr = new Cons(d.car, Lisp.nil);
cur = cur.cdr as Cons;
c = d;
}
return(ret);
}
public void EqualsDoesValueComparison()
{
Cons a = CreateComplicatedCons();
Cons b = CreateComplicatedCons();
Expect(a.Equals(b));
Expect(a, EqualTo(b));
}
