At Thu, 17 Mar 2011 16:12:22 -0400, Matthias Felleisen wrote: > > On Mar 17, 2011, at 4:10 PM, Matthew Flatt wrote: > > > At Thu, 17 Mar 2011 15:53:51 -0400, Matthias Felleisen wrote: > >> That's the heart of the question, its distillation to a one-liner. > >> > >> The real question how a list can __be__ a stream and how a LR stream can > >> __be__ a stream. > > > > It's in the same way that a list can be a sequence and a vector can be > > a sequence. > > > > The intent is that "stream" is an API that can be implemented for > > multiple representations. The representations of streams created by > > `stream-cons' and `cons' are different, but the `stream-empty?', > > `stream-first', and `stream-rest' operations can support both of those > > representations (and more). > > > > This might be a generalization of "stream" as it is sometimes used (I'm > > not sure), and we have already discarded an attempt to generalize > > "generator". The difference is that generators support some operations > > (such as arguments to the generator) that are not be supported by > > stateful sequences in general. In contrast, functional sequences in > > general support any operation that `stream-cons'-streams support. It's > > just a question of how the stream is represented. > > > I disagree only because of the lazy nature of stream __construction__, > the potential confusion for first-timers, and the potential confusion with > some srfi or other.
Can you provide an example that would create confusion? _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
