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. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
