From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric Schulte" Subject: Re: [babel] re-hash cached blocks on each execution? or, force re-hash? Date: Mon, 12 Jul 2010 12:35:27 -0700 Message-ID: <878w5gbihz.fsf@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from [140.186.70.92] (port=38868 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OYOnM-0006AM-Jf for emacs-orgmode@gnu.org; Mon, 12 Jul 2010 15:36:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OYOnE-0005i8-1x for emacs-orgmode@gnu.org; Mon, 12 Jul 2010 15:35:58 -0400 Received: from mail-px0-f169.google.com ([209.85.212.169]:51538) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OYOnD-0005hm-KZ for emacs-orgmode@gnu.org; Mon, 12 Jul 2010 15:35:55 -0400 Received: by pxi7 with SMTP id 7so2600353pxi.0 for ; Mon, 12 Jul 2010 12:35:54 -0700 (PDT) List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: Austin Frank Cc: emacs-orgmode@gnu.org Hi Austin, You've found an error. The hash should be updated every time a new result is inserted into the buffer. I've just pushed up a fix which I believe should take care of this error. Please let me know if any problems persist, or if some portion of your request remains unfulfilled. Thanks -- Eric Austin Frank writes: > Hello! > > I would find it extremely useful if the org-babel-execute-* family of > commands re-hashed the executed blocks on each execution, or, > alternatively, accepted a prefix argument that meant "re-execute this > block even if cached, and replace the cache-hash if necessary". > > Currently, if a block is cached, when I change something inside the > block and then execute the block again, the hash in the #+results line > doesn't change. In cases where the contents of the block change but the > output of the block does not, this makes it very difficult to tell > whether the block has been re-executed or not. > > If there are good reasons not to re-hash the block on each execution and > update the hash in the results line, I would like to be able to force > this behavior. In cases where I know that I want the block to be > re-hashed and re-executed, it seems like C-u C-c C-c or C-u C-u C-c C-c > would be a natural and org-ish way to force this. > > Here's a simple test case: > > * elisp example > #+source: elisp-test > #+BEGIN_SRC emacs-lisp :cache yes > (print "hello world") > (print "re-hash and re-execute, please!") > #+END_SRC > > #+results[f6dfc164b16889f1569fcd3242ba3de721853bc8]: elisp-test > : hello world > > Now I change the above block in place (but reproduce the changes > sequentially here): > > #+source: elisp-test > #+BEGIN_SRC emacs-lisp :cache yes > (print "hello world") > (print "re-hash and re-execute, please!") > #+END_SRC > > #+results[f6dfc164b16889f1569fcd3242ba3de721853bc8]: elisp-test > : re-hash and re-execute, please! > > Note that the block changed, and the results changed, but the hash did > not. > > Now we change it again, in a way that doesn't change the output: > > #+source: elisp-test > #+BEGIN_SRC emacs-lisp :cache yes > (setq four (+ 2 2)) > (print "hello world") > (print "re-hash and re-execute, please!") > #+END_SRC > > #+results[f6dfc164b16889f1569fcd3242ba3de721853bc8]: elisp-test > : re-hash and re-execute, please! > > Again the block changed, but this time the results did not change and > neither did the hash. This makes it very hard to tell whether the code > has been re-executed or not. If the hash changed when the block > changed, I could tell that the new code had been detected and run. > > Finally, we check whether the previous change was actually evaluated: > > * elisp test > #+source: elisp-test > #+BEGIN_SRC emacs-lisp :cache yes > (setq four (+ 2 2)) > (print "hello world") > (print "re-hash and re-execute, please!") > (print four) > #+END_SRC > > #+results[f6dfc164b16889f1569fcd3242ba3de721853bc8]: elisp-test > : 4 > > So the block is re-evaluated when it's changed, but the hash isn't > updated. The only way we can tell if an altered block is re-run is if > the output changes, but that won't necessarily be the case for every > change in a block. It would be very useful if the block were re-hashed > before each execution, and the cache line updated whenever the hash > changes. One possible solution is to force re-hashing and re-execution > with a prefix argument (or double prefix argument, if preferred). > > > Thanks, > /au