Category Archives: Emacs Workout

I’ve got so used to using visual-line-mode in Emacs that I sometimes need reminding there are other ways of setting out work.  Well, that’s what the Emacs Work-Out is all about…

visual-line-mode wraps words at the boundaries of the editor, rather like a word processor does. This can sometimes be a nuisance, particularly when embedding source code in documents.

One solution is to go back to using fill-paragraph. I’m going to set the fill column to 50, for no good reason.

C-x f 50        Set fill column to 50

Now write or copy some text into Emacs.  I'm going
to use this paragraph.  When I finish typing this
sentence I hit M-q right about now...

..and the paragraph is automatically wrapped at the extent of the fill column. You’ll notice I didn’t hit M-q for this paragraph.

What about all those extra carriage returns that get added? Well, if they bother you that much you can use this function and key definition written by Stefan Monnier to unfill-paragraphs.

The chances are, however you won’t need it very often. Most of the stuff I write is exported using org-export before it’s published (see My Emacs Writing Setup for more details)

Export ignores single returns so

a
b
c

becomes a b c on export. In other words, filled paragraphs are exported as, well, paragraphs.

If you can’t be bothered hitting M-q all the time, try setting auto-fill-mode or refill-mode.

Don’t forget you can use whitespace-mode to see non-printing characters and get a better idea of what’s going on.

M-x refill-mode
M-x whitespace-mode

Fill prefixes are an old fashioned method of
;; writing comments in code.  I've set a fill
;; prefix of ;; on this paragraph and hit M-q.
;; Note how the first line isn't prefixed

C-x .      Set fill prefix as text up to the point.
C-o        Add fill prefix to line

M-x set-justification-full
M-x set-justification-left
M-x set-justification-center
M-x set-justification-right
M-x set-justification-none

Sacha Chua writes here about developing microhabits. It’s an article close to my heart, in fact, it’s the reason that I write the Emacs workout. Sacha’s article was inspired in turn by this tweet from Frederik Appelburg

Using transpose-chars is a litmus test. If you care enough to save keystrokes to internalize C-t, then you must be a power user.

I agree with Frederik: I use C-t all the time for that very reason (in fact I’ve written elsewhere that my litmus test is do you use M-c to capitalise words?).
But Frederik got me thinking about M-t. How often do I have to transpose a word?

Transpose two lines, yes, transpose a sentence. Well, when I’m editing stories, I do this a lot. But I rarely find myself transposing words.
Emacs has five built in transpose commands:

C-t transpose-chars Transpose the two letters.
M-t transpose-words Switch two words.
C-x C-t transpose-lines Switch two lines.
transpose-sentences Switch two sentences.
transpose-paragraphs Switch two paragraphs.

The trouble is, there is no key binding for the last two, the ones I’m most likely to use. Well, Emacs was made to be customised, it says so in the name. I could have added a couple of extra key bindings, but for various reasons I chose to use aliases, and so I added the following code to my .emacs file.

1 (defalias 'ts 'transpose-sentences)
2 (defalias 'tp 'transpose-paragraphs)

Now I just move the cursor between two sentences or paragraph, hit M-x ts or M-x tp and that’s it.

It’s such a simple customisation, and one I should have done years ago. But there you go: you have to work hard to be lazy.

Org-mode allows you to use Babel. As it says in the manual:
Babel is Org-mode’s ability to execute source code within Org-mode documents

Here’s a bit of Java, wrapped up in Babel

#+BEGIN_SRC java :classname example
    public class example
    {
            public static void main (String args [])
            {
                System.out.println("Go Babel!");
            }
    }
#+END_SRC

Put the point in the block and

C-c '      to edit the code
C-c C-c     to run the code

In the past, I never used Babel as often as I should, mainly because I could never quite remember the syntax.

Then I had the idea of adding Babel to YASnippet.  I added the following to my org-mode snippets:

# -*- mode: snippet -*-
# name: jbabel
# key: jbabel
# --
#+BEGIN_SRC java :classname $1
    public class $1
    {
            public static void main (String args [])
            {
                System.out.println("$0");
            }
    }
#+END_SRC

… and now I just have to type jbabel and hit tab to have my Babel block ready to go.

It works with ditaa too. As I could never quite remember all the codes when I needed them, I just put a few of ones I used most frequently in a YASnippet example:

# -*- mode: snippet -*-
# name: ditaa babel
# key: dbabel
# --
#+begin_src ditaa :file $1.png
/-----------------\
| Things to do    |        +-----+
| cGRE            |    |{s}  |
| o Cut the grass *-+----->|     |
| o Buy jam       |    |     |
| o Fix car       |    +-----+
| o Make website  |
\-----------------/
#+end_src

And here’s what it looks like when converted (if you’re reading this on Google+, you might want to head over to my website: TonyBallantyne.com to see the image)

A whole workout on deleting whitespace? It’s worth it…

You might want to start by enabling whitespace mode: M-x whitespace-mode

Let’s start with closing the gap between lines…

M-^      Join a line with the previous line
C-x C-o       Delete white space after current line up to next line.

What’s great about the above two commands is that the point can be anywhere on the line when you call them.

The next two commands aren’t quite so quick to use, the point needs to be in the whitespace you’re trying to delete.

M-SPACE   Delete all spaces but one between two characters
M-\            Delete all whitespace between two characters

Don’t forget the rectangle commands:

C-x r k      Kills the rectangle between the point and the mark.

Find out more about how to use that command in this workout.
Lastly, removing line breaks. Use

C-M-%  query replace regex
Use C-q C-m or C-q C-j to find the line breaks.

I heard a lot of people talking about Scrivener so I downloaded a trial copy (on Windows, there’s no Linux version, sadly…) and gave it a try.

It seems like a suitable tool for writers to use, it comes with a nice tutorial, and I’d recommend that anyone give the free 30 day trial a go, (this despite the fact the company behind it are called Literature and Latte).

I still prefer Emacs, though. Most of the features that Scrivener offers are easily replicable in Emacs. If you’ve been following my Emacs Writing Tips you’ll have been doing something similar anyway.

One thing I did like about Scrivener was the corkboard, a place where you could pin synopsis cards and move them around whilst you’re putting your ideas in order. This is a really good idea, and one thing that Emacs can’t replicate so well.

Here’s a work around

The idea is quite straightforward

1. Write your synopsis in headings
2. Move them up and down using M-<up> and M-<down>

It’s not as nice as the corkboard, but if you want a graphical interface, you’re using the wrong program.

It’s also worth mentioning org-tree-to-indirect-buffer, here. This allows you to replicate the document map in Microsoft word. It’s easiest to try this out for yourself

1. Open an org file in Emacs
2. Navigate to the subtree you want to edit
3. C-x 3 to split the window vertically (org-tree-to-indirect-buffer defaults to a vertical split)
4. C-c C-x b to open the narrowed subtree in the other frame

It all sounds rather complicated, but it’s really quite straightforward, and very useful…

You might want read the post on Regexp Builder before attempting these…

Here’s an example of a British Postcode: OL1 3SQ. It has the format 2 letters and a digit, space, 1 digit and two letters. The following emacs regex finds this type of postcode:

“[A-Z]\{2\}[0-9] [0-9][A-Z]\{2\}”

1. Write a regex to find postcodes of the type W1 1AA
2. Write a regex to find postcodes of the type RM12 4JJ
3. Write one regex that finds all three types of postcode: OL1 3SQ, W1 1AA and RM12 4JJ
4. Write a regex that finds simple email addresses of the form this@that.com
5. Now extend the regex to find email addresses of the form this.that@other.co.uk
6. Now write a general email regex that will find all properly formed email addresses
7. Google the form of an ISBN (There are two standards). Write a regex to find ISBNs
8. Write a regex that can find unnecessary white space in a line of text

This      line     has              unnecessary      white space    .
|              So does this line   |
This line does not.

Finally…

“He said ‘Have you got the time?’” “Why didn’t he look at his watch?”
Write a regex that can find the left single quotes: ‘and right double quotes: ” in the above conversation.

Here are some random Dired mode tips:

w       copies names of marked files to kill ring.
C-0 w   copies absolute file name
C-u     copies names relative to Dired’s current directory

-rw-rw-r--  1 ***** *****  110537 Mar 24 13:07 planner.org
-rw-rw-r--  1 ***** *****   60688 Sep  3  2013 planner.org.~1~
-rw-rw-r--  1 ***** *****   60688 Sep  3  2013 planner.org.~2~
-rw-rw-r--  1 ***** *****  112046 Mar 18 16:37 planner.org.~860~
-rw-rw-r--  1 ***** *****  112079 Mar 18 16:40 planner.org.~861~
-rw-rw-r--  1 ***** *****  112133 Mar 18 16:55 planner.org.~862~
-rw-rw-r--  1 ***** *****  112133 Mar 18 16:55 planner.org.~863~
-rw-rw-r--  1 ***** *****  112196 Mar 20 15:16 planner.org.~864~

% m ~   Mark all backup files
k       Remove them from view

(require 'dired-x)
(setq dired-omit-mode t)

M-x make-directory RET RET