private static IToken Acquire(IToken arg0, IToken arg1)
{
var key = Tuple.Create(arg0, arg1);
if (Cache.TryGetValue(key, out var cached))
{
return(cached);
}
IToken x;
if (arg1 == null)
{
x = new LtOperator(arg0);
}
else
{
var x0 = AlienMessageParser.Reduce(arg0);
var x1 = AlienMessageParser.Reduce(arg1);
x = x0.AsValue() < x1.AsValue() ? (IToken)KComb.Acquire() : FComb.Acquire();
}
Cache[key] = x;
return(x);
}
public IToken Apply(IToken arg)
{
var x0 = AlienMessageParser.Reduce(arg);
if (x0 is NilOperator)
{
return(KComb.Acquire());
}
else if (x0 is ConsOperator)
{
return(FComb.Acquire());
}
else
{
throw new InvalidOperationException();
}
}