content/blog/2012/10/why-i-two-space.markdown @ 6d36ebb4ecee

+++
title = "Why I Two-Space"
snip = "You can pry my extra spaces from my cold, dead hands."
date = 2012-10-12T10:10:00Z
draft = false

+++

If you look at [the source code][source] for this blog, you might notice that
all my blog posts (written in [Markdown][]) have two spaces after every period.

Every so often [this Slate article][slate] makes the rounds and annoys me.  This
time I figured I'd write a blog post/rant to get it off my chest once and for
all: two-spacing is equal or superior to one-spacing in all non-trivial ways.

[source]: https://bitbucket.org/sjl/stevelosh/src/tip/content/blog
[Markdown]: http://daringfireball.net/projects/markdown/
[slate]: http://www.slate.com/articles/technology/technology/2011/01/space_invaders.html

<div id="toc"></div>

The Arguments for One-Spacing
-----------------------------

If you read the aforementioned Slate article you'll see that it presents a total
of three arguments in favor of single-spacing after a period:

1. Many professional typographers find two-spacing ugly (though they have no
   actual evidence of its effects on readability).
2. It's less work to press the space bar once instead of twice.
3. It's pretty much arbitrary anyway, so *why not*?

You might also infer from the article's tone that "you get to feel superior to
those Neanderthals that use two spaces" is another argument in favor of it, but
I'll leave that one out because it can go both ways.

Let's go through these arguments one by one and see how they hold up.

Effort
------

I don't think the "it's more effort to press the space bar twice" argument is at
all compelling.  The extra space *may* account for around half a percent of the
keystrokes you type, depending on how long your sentences tend to run (mine
usually end up fairly long, as you can see).

Not only is it not a large portion of your keystrokes, but the space bar has
your two strongest digits dedicated solely to it!  If any fingers are going to
wear out from typing, it won't be your thumbs.

You could get pedantic and mention increased file size as a disadvantage of two
spacing, but let's not quibble about a few bytes when I can hold 32 gigabytes on
an SD card the size of a postage stamp.

Two-Spacing is Ugly
-------------------

The Slate article is correct is saying that many professional typographers think
two-spacing is ugly.  My copy of [The Elements of Typographic Style][elements]
agrees.  However, there's more to the issue than a single blanket rule.

[elements]: http://www.amazon.com/dp/0881792063/?tag=stelos-20

### Source and Presentation

If you're reading this in a web browser and look closely, you'll notice that
there's only one space between each sentence.  I said I used two, so what
happened?

Web browsers, by default, collapse successive whitespace into a single space when it
renders the HTML.  You could put a thousand spaces between sentences in the
source and it would still come out single-spaced.

Another widely-used format, LaTeX, splits the difference and actually uses
somewhere between one and two spaces (by default).

The key idea here is that what you type and what the end user actually reads are
two different things.  They don't need to be bound together.  It's possible to
type two spaces but get one in your output (or in LaTeX's case: an even more
pleasing "one and a bit").

If you're using a WYSIWYG editor like Microsoft Word this may not be the case.
For the high school students typing up papers for class: sure, go ahead and
single-space.  But if you're still using Word to type up things like books, long
blog posts, or technical documentation, you're doing yourself a disservice.
Learn to use a system like LaTeX so your source and rendered output aren't
locked together.

This means that "two-spacing looks ugly" doesn't imply "you should not type two
spaces when you write".  It *actually* implies "you should use a system that
results in single-spacing when rendered", and most of the common ones today will
do exactly that.

### Typewriters

So we've seen that the "extra spaces take more effort" argument isn't
convincing, and that "two-spacing in the final output is ugly" doesn't prevent
you from using two spaces in the input.

But so far I haven't given you any reason *for* using two spaces.  That's the
Slate article's third argument: "it's arbitrary anyway, so you may as well use
one".

Let's fix that by examining the common holier-than-thou put-down of "two-spacing
was useful back when people used *typewriters*, you dinosaur!".

To his credit, the Slate author correctly points out that it's not the fact that
people used typewriters that made two-spacing popular, it was the fact that
*typewriters used monospaced fonts*.  Most people miss that logical leap.

Unfortunately he follows that up with:

> Here's the thing, though: Monospaced fonts went out in the 1970s.

For the average person typing up a school paper here and there, sure.  But for
many people doing a large amount of writing for LaTeX books and papers,
technical documentation, code comments, mailing lists, blog posts, and lots of
other things, it's simply *wrong* for one big reason:

**Text editors use monospaced fonts!**

It doesn't matter what editor you use.  Vim, Emacs, TextMate, Sublime Text,
Eclipse, Gedit, Notepad++?  *All* of them use monospaced fonts.

Going back to the typewriter quip, this means that if people used two spaces
when writing on typewriters because it looked better, then using two spaces in
a text editor will look better.  And we know that because there's a distinction
between source and presentation in non-WYSIWYG contexts, we can use separate
strategies for each.

We can have our cake and eat it too!  We can type two spaces after a period to
make our text look better as we write, revise, and edit it, and then render it
to single-spacing (or "space-and-a-half-ing") to give our readers a beautiful
reading experience with pleasant spacing.

So now two-spacing has a real advantage over single-spacing.  That's enough to
make it preferable.  But let's look at one more advantage for power users, just
to seal the deal.

Power
-----

If you use [Vim][] to edit text, you're probably familiar with its "text
objects".  Text objects are what let you move and act on whole chunks of text at
a time.  For example, instead of deleting a word letter-by-letter you can use
`daw` to "delete around word".

Vim comes with a "sentence" text object built-in.  You can move around your
document sentence-by-sentence with `(` and `)`, and yank/delete/change/etc
entire sentences with `cas` ("change around sentence") and so on.

You can probably guess where this is going.  If you single-space sentences Vim
will do its best to "do the right thing", but inevitably gets tripped up when
you've got punctuation in your sentence.  For example:

    Bob started speaking. Hello, Mr. Smith! How are you today?
                                        ^
                                        cursor

What happens when you tell Vim to "delete around sentence" now?

    Bob started speaking. Hello, Mr. How are you today?
                                      ^
                                      cursor

Well that's not right!  Vim can't easily tell the difference between the period
after "Mr" and the end of a sentence.  What happens if you type your prose with
two-spacing instead?

    Bob started speaking.  Hello, Mr. Smith!  How are you today?
                                         ^
                                         cursor
    Bob started speaking.  How are you today?
                           ^
                           cursor

This time Vim is able to delete the sentence correctly!  Note that you'll need
to make sure to `set cpo+=J` in your `~/.vimrc` file to tell Vim "don't worry,
I'm using two spaces like a sane person" for this to work.

Two-spacing provides more semantic information, which means that software can
parse and work with it more easily.  I'm sure Emacs has something similar, and
if you or someone else ever needs to parse your writing programatically they'll
have an easier time.

Final Score
-----------

To recap, the arguments *for* single-spacing are:

1. Two-spacing is ugly in proportional fonts.
2. It's less work to press the space bar once instead of twice.
3. It's pretty much arbitrary anyway, so why bother with two?

Number 1 is irrelevant, because writing and rendering are (except in trivial
cases) two orthogonal activities.

Number 2 isn't very convincing.

Number 3 is false, because two-spacing gives you two advantages over
one-spacing:

1. It looks better in your editor.
2. It gives you more power when editing and parsing.

So the next time you see that arrogant Slate article, feel free to be arrogant
right back.  Wield your extra spaces proudly, because they give you both comfort
and power!

[Vim]: http://www.vim.org/