Some time before the release of Clojure 1.0, there didn't used to be any
such thing as an empty sequence.  You either had a (lazy) sequence, or nil.
 This made it easy to use sequences as emptiness tests, but had the cost
that a lazy sequence wasn't fully lazy because anything that returned one
had to attempt to evaluate the first item in order to determine whether
there was anything to return or not.

[ There are some obsolete notes describing the change here:
http://clojure.org/lazy  for the historically curious.  Or perhaps here:
http://clojure.org/lazier (And the 'streams' referred to in those docs
refer to this failed experiment: http://clojure.org/streams).  Basically
lazy-cons was replaced by lazy-seq. ]

-- 
Dave

-- 
-- 
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your 
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
--- 
You received this message because you are subscribed to the Google Groups 
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.


Reply via email to