On Jun 12, 2009, at 7:52 PM, Wrexsoul wrote:
> Well, I did it. Made implementing lazy seqs that require stateful
> generator functions easy, that is:
>
> (defn files-and-dirs-recursive [dir]
> (super-lazy-seq [stack [(to-file dir)]]
>(if-not (empty? stack)
> (let [file (first stack) s
On Jun 15, 4:58 am, Wrexsoul wrote:
> Eh. That didn't occur to me. It could be combined with the meta-nil
> trick, too:
>
> (defn custom-lazy-seq [genfn]
> (map #(first %)
> (take-while (complement nil?)
> (repeatedly genfn
>
> where the genfn returns nil for no-next-item and [i
On Jun 14, 2009, at 12:53 PM, James Reeves wrote:
>
> On Jun 14, 6:32 pm, Wrexsoul wrote:
>> I wrote super-lazy-seq because repeatedly can't generate a finite
>> sequence. It just spat out
>>
>> (File1 File2 File3 File4 nil nil nil nil nil nil nil ...
>
> Well, you could wrap it in take-while:
On Jun 14, 2:53 pm, James Reeves wrote:
> On Jun 14, 6:32 pm, Wrexsoul wrote:
>
> > I wrote super-lazy-seq because repeatedly can't generate a finite
> > sequence. It just spat out
>
> > (File1 File2 File3 File4 nil nil nil nil nil nil nil ...
>
> Well, you could wrap it in take-while:
>
> (de
On Jun 14, 6:32 pm, Wrexsoul wrote:
> I wrote super-lazy-seq because repeatedly can't generate a finite
> sequence. It just spat out
>
> (File1 File2 File3 File4 nil nil nil nil nil nil nil ...
Well, you could wrap it in take-while:
(defn custom-lazy-seq [stream]
(take-while (complement n
On Jun 14, 9:39 am, James Reeves wrote:
> Okay, but don't underestimate the power of higher level functions. I
> don't know whether it would apply to your code, but the repeatedly
> function can be used to create a lazy seq from a function with side-
> effects.
>
> For example:
>
> (defn custom
On Jun 14, 4:37 am, Wrexsoul wrote:
> Seems to me that unless you completely consume the sequence, it will
> leak a file handle.
That's true, but that's a problem that affects all seqs. There's no
current way to mark a seq that comes from a stream as being discarded
or closed, except by closing
On Jun 14, 6:37 am, Wrexsoul wrote:
> On Jun 13, 11:07 pm, James Reeves wrote:
>
> > For instance, lets say I want to return a lazy list of all the lines
> > in all the files in a directory tree:
>
> > (use '(clojure.contrib java-utils
> > duck-streams))
>
> When cloju
On Jun 13, 11:07 pm, James Reeves wrote:
> For instance, lets say I want to return a lazy list of all the lines
> in all the files in a directory tree:
>
> (use '(clojure.contrib java-utils
> duck-streams))
When clojure.contrib releases version 1.0, that might be an op
On Jun 14, 3:21 am, Wrexsoul wrote:
> It lets you write the generator in a style similar to loop/recur, and
> generally in half the code. And, it demonstrates the kinds of things
> you can do with macros.
Ahh, I see. That could be useful under some circumstances. However,
most Clojure functions
On Jun 13, 9:24 pm, James Reeves wrote:
> On Jun 13, 4:18 am, Wrexsoul wrote:
>
> > Between files-and-dirs and file-lines-seq I think I have saved as many
> > lines of code as are in the macro+helper fns, so those are at break-
> > even.
>
> I'm not completely sure what benefit super-lazy-seq is
On Jun 13, 4:18 am, Wrexsoul wrote:
> Between files-and-dirs and file-lines-seq I think I have saved as many
> lines of code as are in the macro+helper fns, so those are at break-
> even.
I'm not completely sure what benefit super-lazy-seq is meant to have.
Could you perhaps give an example writ
Heh. Thought of an improvement:
(defn make-atom-setter-fn-expr [names skip?]
(let [arglist-1 (map #(gensym %) names)
arglist (vec (if skip? arglist-1 (cons (gensym 'item)
arglist-1)))]
`(~(if skip? 'skip-item 'next-item)
~arglist
~@(map (fn [nm gs] (list 'reset! nm gs))
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