M-, n- and other dashes

[jack]

I was under the impression that there were uses for mid-height horizontal lines in text:

1. Hyphenating words or joining words together.
2. (Binary or unary) Minus sign.
3. Separating sentences, eg. "I was -- as you may know -- pedantic."
4. Indicating ranges, eg. "A temperature of 20-25 celcius"
5. Joining things that already have hyphens in.
6. Joining things not to modify one by the other, eg. "US-UK tensions"
7. Introducing quotes or attributions

I *thought* that 1 was a hyphen, 2 was a minus sign, 3 was an em-dash, 4,5 and 6 were en-dashes, and 7 was a specially long dash that was generally treated the same as an em-dash.

And I *though* that typographically you would ideally have a dash narrower than a letter called a hyphen used as a hyphen, a dash as wide as an 'n' used for an en-dash, a dash as wide as an 'm' used for an em-dash, and a dash of unknown width used as a minus sign. But that normally (if you don't have unicode or don't think it's an important distinction) you use a single dash to represent hyphen and minus (generally the one generated by a standard keyboard), and often as an 'n' dash as well, and often two together as an em-dash. (And that em-dashes may or may not have spaces round, and the others shouldn't.)

However, people in the pub who edit things said I was misled somewhere along the line. I've certainly only picked this up (Bill Walsh and wikipedia feature heavily). I know it's not important, but does anyone want to update me?

Comments

[hoiho.livejournal.com]

Well, TeX seems to share your impressions...

[tienelle.livejournal.com]

American standard style for (3) seems to be to use an em-dash and no spaces: I was—as you may know—pedantic. British style is to use an en-dash and spaces: I was – as you may know – pedantic. A minus sign is not a dash; it's its own symbol which I think is about as wide as an en-dash in most typefaces. Joining things which already have hyphens is just a losing proposition.

An em is a useful unit of length: it's the point size of the current typeface. In most typefaces not designed by monkeys, this is about the width of the character M. An em-dash is one em long. An en-dash is half as long as an em-dash, which, subject to earlier simian considerations, is about the width of an N.

All of this has no more authority than my own observation and some of the LaTeX documentation.

[beckyc.livejournal.com]

3. Separating sentences, eg. "I was -- as you may know -- pedantic."

Are you sure those are sentences?