On Thu, Nov 5, 2009 at 7:24 PM, MarkSwanson <mark.swanson...@gmail.com>wrote:
> On Nov 5, 7:00 pm, MarkSwanson <mark.swanson...@gmail.com> wrote:
> > (def
> > #^{:arglists '([coll])
> > :tag clojure.lang.ISeq
> > :doc "Returns a seq of the items after the first. Calls seq on its
> > argument. If there are no more items, returns nil."}
> > next (fn next [x] (. clojure.lang.RT (next x))))
> >
> > PROBLEM: seq is not called on its argument.
>
> Ok, I see RT.next(x) is called and the implementation is:
>
> static public ISeq next(Object x){
> if(x instanceof ISeq)
> return ((ISeq) x).next();
> ISeq seq = seq(x);
> if(seq == null)
> return null;
> return seq.next();
> }
>
> 1. if ISeq, return the next item in the sequence.
> 2. else, (seq coll)
> I propose the docs should read something like this:
>
> (next coll)
> :doc "If coll is not a seq, turn coll into a seq. Returns a seq
> of the coll after the first item.
> If coll has no more items, returns nil."}
I wouldn't bother. The semantics are essentially what the present docs say;
it's just that where calling seq on its argument would just call a method
whose body is "return this;" it skips that no-op for efficiency. (At least,
the body of ASeq.seq() is "return this;"; are there any ISeq implementations
where it isn't?)
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
