Re: Lazy-seq of a binary file

On Wed, Dec 14, 2011 at 11:47 PM, Simone Mosciatti mweb@gmail.com wrote: Ok thank you so much, i got it. Thanks again ;-) You're welcome. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to

Re: Lazy-seq of a binary file

On Wed, Dec 14, 2011 at 12:04 AM, Simone Mosciatti mweb@gmail.com wrote: Thank you so much, just one last thing, why you use a char-array ? Reader returns chars. If I want use a byte-array, and no map all the whole sequence ? Use an InputStream rather than a reader if you're reading

Re: Lazy-seq of a binary file

Ok thank you so much, i got it. Thanks again ;-) Simone On Dec 14, 3:22 am, Cedric Greevey cgree...@gmail.com wrote: On Wed, Dec 14, 2011 at 12:04 AM, Simone Mosciatti mweb@gmail.com wrote: Thank you so much, just one last thing, why you use a char-array ? Reader returns chars. If I

Re: Lazy-seq of a binary file

Here's a version I hacked up a while ago: https://gist.github.com/1472163 -S -- 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

Re: Lazy-seq of a binary file

No, I'm sure to not use all the sequence, so I will follow your second advice, but... Cause of my non-perfect english I've not really understand the last part. Who is the caller ? You suggest something like this: (let [fl (clojure.java.io/reader path/filename) rd (lazy-reader fl)]

Re: Lazy-seq of a binary file

On Tue, Dec 13, 2011 at 10:14 PM, Simone Mosciatti mweb@gmail.com wrote: No, I'm sure to not use all the sequence, so I will follow your second advice, but... Cause of my non-perfect english I've not really understand the last part.  Who is the caller ?  You suggest something like this:

Re: Lazy-seq of a binary file

Ok, now by now i think to have understand... To do right, I should build a macro similar to let where I pass the filename and after execute the body close the stream, right ? On Dec 13, 9:42 pm, Cedric Greevey cgree...@gmail.com wrote: On Tue, Dec 13, 2011 at 10:14 PM, Simone Mosciatti

Re: Lazy-seq of a binary file

On Tue, Dec 13, 2011 at 11:12 PM, Simone Mosciatti mweb@gmail.com wrote: Ok, now by now i think to have understand... To do right, I should build a macro similar to let where I pass the filename and after execute the body close the stream, right ? Easier to just use the pre-existing one:

Re: Lazy-seq of a binary file

Where by now: (defn lazy-reader [fl] (assert ...) (lazy-seq (cons (.read fl) (lazy-reader fl The first one ? This means that I haven't understand nothing, right? (I'm so sorry for this stupid question... :embarassed: ) On Dec 13, 10:23 pm, Cedric Greevey

Re: Lazy-seq of a binary file

On Tue, Dec 13, 2011 at 11:33 PM, Simone Mosciatti mweb@gmail.com wrote: Where by now: (defn lazy-reader [fl]     (assert ...)     (lazy-seq         (cons (.read fl) (lazy-reader fl The first one ? Er, buffering of the I/O is probably preferable, but that would probably work OK in

Re: Lazy-seq of a binary file

Thank you so much, just one last thing, why you use a char-array ? If I want use a byte-array, and no map all the whole sequence ? On Dec 13, 10:39 pm, Cedric Greevey cgree...@gmail.com wrote: On Tue, Dec 13, 2011 at 11:33 PM, Simone Mosciatti mweb@gmail.com wrote: Where by now: (defn

Re: Lazy-seq of a binary file

If I do just something like that: (def fl (clojure.java.io/reader /path/to/file)) (defn lazy-reader [fl] (lazy-seq (cons (.read fl) (lazy-reader fl Can work ? (0.03696 ms for 500 char) Possible problem ? On Dec 11, 9:49 pm, Stephen Compall stephen.comp...@gmail.com wrote: On

Re: Lazy-seq of a binary file

On Mon, 2011-12-12 at 10:21 -0800, Simone Mosciatti wrote: (defn lazy-reader [fl] (lazy-seq (cons (.read fl) (lazy-reader fl Can work ? (0.03696 ms for 500 char) Possible problem ? You need a termination case; your lazy-reader currently always yields an infinite sequence.

Re: Lazy-seq of a binary file

I thought to just put it into a take... (take number-of-byte-necessary (lazy-reader (clojure.java.io/reader path/to/file))) On Dec 12, 12:34 pm, Stephen Compall stephen.comp...@gmail.com wrote: On Mon, 2011-12-12 at 10:21 -0800, Simone Mosciatti wrote: (defn lazy-reader [fl]     (lazy-seq

Re: Lazy-seq of a binary file

Ok, I found a possible problem, if i try to put all together, so write something like this: (defn lazy-reader [filename] (with-open [fl (clojure.java.io/reader filename)] (loop [bite (.read fl)] (lazy-seq (cons (bite) (recur (.read fl))) Obviously doesn't work... Any

Re: Lazy-seq of a binary file

On Mon, 2011-12-12 at 20:03 -0800, Simone Mosciatti wrote: Any suggest of how fix that ? In general, avoid loop. Specifically, try using letfn or (fn SOME-NAME-HERE [args...] ...) as your recursion target. -- Stephen Compall ^aCollection allSatisfy: [:each|aCondition]: less is better -- You

Re: Lazy-seq of a binary file

You also probably want more efficiency. Try something closer to: (defn lazy-reader [filename] (let [rd (fn [rdr] (let [buf (char-array 4096) n (.read rdr buf 0 4096)] (condp == n -1 (.close rdr) 0 (recur rdr)

Lazy-seq of a binary file

Hi Guys, I'm pretty new of clojure so sorry for the maybe stupid question... Anyway, i'm looking for read a file byte by byte, perfect would be get a lazy-seq of every byte in the file, it's looks, for me, very weird that there isn't a built-in or some easy way to do that, but I haven't find

Re: Lazy-seq of a binary file

On Sat, 2011-12-10 at 23:13 -0800, Simone Mosciatti wrote: Anyway, i'm looking for read a file byte by byte, perfect would be get a lazy-seq of every byte in the file, it's looks, for me, very weird that there isn't a built-in or some easy way to do that The tradeoffs aren't universal enough