Elisp: help on string operations for fast file visiting

Elisp: help on string operations for fast file visiting

[Karl Voit]

Hi!

For Memacs[1], I'd like to come up with a very fast Org-mode method to
open files independent of their location on your disk. I accomplished
everything necessary so far. However, I've got issues writing an elisp
function for extracting a file and sending it to a function that calls
the operating system app associated. My elisp knowledge is still too
bad :-(

What I've got is a string (from the lookup) which contains:
(1) nothing
(2) one line like "** <2008-06-17 21:43> [[file:/home/user/dir/2008-06-17 description of file.odp][2008-06-17 description of file.odp]]"
(3) multiple lines like (2) but with different files and links

I'd like to get a "Sorry" message for (1). Easy, if only I know how to
count lines in strings (as opposed to buffers).

For (2) I'd like to call my-open-in-external-app(string).

For (3), I'd like to use the first line just as in (2) as a starter. I
do have some ideas on gracious "error-recovering" on this one but
that's maybe too complicated to code for now: getting rid of
substrings delimited by not-'a-zA-Z0-9' from the end of the link
until a match is found; message in case there is no unique match which
could be found this way.

Could you please help me here? It'd help all users of the file index
module of Memacs.


The mini fragment I have so far is following but the regex seems to
be broken:

#+BEGIN_SRC elisp
    (let (
      (result (replace-regexp-in-string "\r?\n$" ""
                        (shell-command-to-string (concat "grep "
                                         "2008-06-17"
                                         " ~/org/memacs/files.org_archive");; hard coded stuff for testing purposes
                                     )
                        )
          )
      )
      (message (concat "result -> " result))
      (re-search-forward " \[\[.+\]\[" nil t 1)
      (let (
        (firstlink ((match-string 1)))
        )
        (message (concat "first link -> " firstlink))
       )
      )
#+END_SRC



[1] https://github.com/novoid/Memacs

-- 
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https://github.com/novoid/extract_pdf_annotations_to_orgmode + more on github

Re: Elisp: help on string operations for fast file visiting

[Alan Schmitt]

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On 2016-11-07 17:27, Karl Voit <devnull@Karl-Voit.at> writes:

> I'd like to get a "Sorry" message for (1). Easy, if only I know how to
> count lines in strings (as opposed to buffers).

You could start by doing (split-string the_string "\n" t) (the last 't'
says to omit the empty strings). So you get a list, possibly empty, of
strings.

Would this help for the rest?

Alan

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Re: Elisp: help on string operations for fast file visiting

[Karl Voit]

* Alan Schmitt <alan.schmitt@polytechnique.org> wrote:
>
> On 2016-11-07 17:27, Karl Voit <devnull@Karl-Voit.at> writes:
>
>> I'd like to get a "Sorry" message for (1). Easy, if only I know how to
>> count lines in strings (as opposed to buffers).
>
> You could start by doing (split-string the_string "\n" t) (the last 't'
> says to omit the empty strings). So you get a list, possibly empty, of
> strings.
>
> Would this help for the rest?

Thanks for the tipp!

John Kitchin sent me some code I have to digest. From the first
look, it should help me to come up with the complete solution I
need. Thanks! I'll report back ;-)

-- 
mail|git|SVN|photos|postings|SMS|phonecalls|RSS|CSV|XML to Org-mode:
       > get Memacs from https://github.com/novoid/Memacs <

https://github.com/novoid/extract_pdf_annotations_to_orgmode + more on github

Re: Elisp: help on string operations for fast file visiting

[John Kitchin]

This is a different approach to what I think you want.

Here is what I assume in this:
1. All the things you want to search for are in a file called
archive.org which is in the same directory you are searching for (use an
absolute path if it is not).
2. You have file links that only have a path, i.e. nothing like
file:test.odp::45
3. You want the query to match some part of the path in a file link.
4. if you click on the link you want, it will open the file in the
external program you want it to open in. This will probably work if they
are always absolute paths, and might be a problem for relative paths
(they would need to be correctly converted to absolute paths).

What it does is get all the file links in the archive.org file that
have a path that matches the query. If there is none, you get a message.
If there is one, it opens it as if you clicked on the link. and if there
is more than one, it prompts you with completing read to choose one,
then opens it.

#+BEGIN_SRC emacs-lisp
(defun memacs-file (query)
  "Open memacs files by QUERY."
  (interactive "sQuery: ")
  (with-current-buffer (find-file-noselect "archive.org")
    (let ((links (org-element-map (org-element-parse-buffer) 'link
		   (lambda (link)
		     (when (string-match query (org-element-property :path link)) link)))))
      (cond
       ((= 0 (length links))
	(message "No files found."))
       ((= 1 (length links))
	(org-open-link-from-string
	 (format "[[file:%s]]" (org-element-property :path (car links)))))
       (t
	(org-open-link-from-string 
	 (completing-read
	  "File: "
	  (mapcar (lambda (link)
		    (format "[[file:%s]]" (org-element-property :path link)))
		  links))))))))
#+END_SRC

For a large archive file, you might be better off with a grep solution,
since this has to parse the file first.



Karl Voit writes:

> Hi!
>
> For Memacs[1], I'd like to come up with a very fast Org-mode method to
> open files independent of their location on your disk. I accomplished
> everything necessary so far. However, I've got issues writing an elisp
> function for extracting a file and sending it to a function that calls
> the operating system app associated. My elisp knowledge is still too
> bad :-(
>
> What I've got is a string (from the lookup) which contains:
> (1) nothing
> (2) one line like "** <2008-06-17 21:43> [[file:/home/user/dir/2008-06-17 description of file.odp][2008-06-17 description of file.odp]]"
> (3) multiple lines like (2) but with different files and links
>
> I'd like to get a "Sorry" message for (1). Easy, if only I know how to
> count lines in strings (as opposed to buffers).
>
> For (2) I'd like to call my-open-in-external-app(string).
>
> For (3), I'd like to use the first line just as in (2) as a starter. I
> do have some ideas on gracious "error-recovering" on this one but
> that's maybe too complicated to code for now: getting rid of
> substrings delimited by not-'a-zA-Z0-9' from the end of the link
> until a match is found; message in case there is no unique match which
> could be found this way.
>
> Could you please help me here? It'd help all users of the file index
> module of Memacs.
>
>
> The mini fragment I have so far is following but the regex seems to
> be broken:
>
> #+BEGIN_SRC elisp
>     (let (
>       (result (replace-regexp-in-string "\r?\n$" ""
>                         (shell-command-to-string (concat "grep "
>                                          "2008-06-17"
>                                          " ~/org/memacs/files.org_archive");; hard coded stuff for testing purposes
>                                      )
>                         )
>           )
>       )
>       (message (concat "result -> " result))
>       (re-search-forward " \[\[.+\]\[" nil t 1)
>       (let (
>         (firstlink ((match-string 1)))
>         )
>         (message (concat "first link -> " firstlink))
>        )
>       )
> #+END_SRC
>
>
>
> [1] https://github.com/novoid/Memacs


-- 
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu

Fast Opening of Memacs Indexed Files (was: Elisp: help on string operations for fast file visiting)

[Karl Voit]

* Karl Voit <devnull@Karl-Voit.at> wrote:
> Hi!
>
> For Memacs[1], I'd like to come up with a very fast Org-mode method to
> open files independent of their location on your disk.

With the help of John Kitchin, I am now able to present you the
solution for the issue:

        http://karl-voit.at/2017/01/01/memacs-grep/

In case you're using Memacs, this function might worth a look.

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