[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Should the car be a stream?



On Wed, 14 Nov 2007, Phil Bewig wrote:

I think I am saying (eq? stream-type promise-type) is #t and Andre is saying
(eqv? stream-type promise-type) is #f.  Both statements are correct.  Since
both stream-type and promise-type are abstract, I can mix them up inside
(streams primitive) without consequence, except that it causes some
confusion.  I guess it is more precise to say that the type of the
stream-car is a promise, not a stream, except that in the implementation
they are the same thing.

I do not agree that it is without consequence.  From

  (stream? (stream-car s)) ==> #t

one would conclude that the car element is always either infinite or a finite
stream ending in stream-null, which is not true.

Andre