Bonobo Conspiracy's Quick Guide to the LaTeX \linebreak command

Luk from 98.232.16.17 at Fri, 17 Jul 2009 06:54:18 +0000:
Could you explain this?

Matt from 67.158.68.132 at Fri, 17 Jul 2009 12:42:50 +0000:
Knuth and Lamport are credited as the creators of TeX and LaTeX respectively. (Both systems are now too big to *really* be the work of single individuals - it's a similar situation to Torvalds and Linux.) They're also each famous for multiple other achievements in computer science. TeX and LaTeX are used to typeset scientific documents.

One common issue in typesetting is how to break paragraphs into lines. It's complicated because, for instance, you're allowed to hyphenate words if one won't fit well on a line, but that's not as good as keeping words whole, and you can stretch or shrink spaces but you don't want to do that too much, and so on. TeX/LaTeX implements a sophisticated algorithm for determining how to do line breaks.

It still isn't perfect. Sometimes it fails and you end up with words that it can't break sticking out into the right margin. At that point, there are several different things you can do. You can insert hints (for instance with the \- optional-hyphen command) that tell the system about places it wouldn't otherwise recognize but where it could insert a line break if necessary. You can rewrite your text to make it break more naturally. You can tell the system to bend the rules and make breaking decisions it would normally consider unacceptably unbalanced. Or you can use \linebreak, which FORCES a line break to occur at a given point whether it looks good or not. That last is almost always the wrong thing to do; for one thing, even if you put the \linebreak in a place that looks good right when you do it, it makes your text very fragile. If you do any rewriting later, or change the margins, you end up with a line break being forced in a place where it doesn't look good and TeX can't compensate because you overrode it. Inserting non-binding hints is much better - then the system can use them if necessary, but won't be forced to use them when they're inapplicable.

Volker from 78.50.244.205 at Sun, 16 Aug 2009 18:31:03 +0000:
I don't know about Lamport, I regard LaTeX as a bit of a foul-up... but TeX's line breaking is by Knuth, so he's the guy who matters here.

Forced line breaks are a bad idea except (perhaps) as a last resort. Use penalties instead to influence line breaking in a controlled way. They are the only way to write macros that work generally, as opposed to one-time kludges. To learn about them, buy Knuth's TeXbook, or download Victor Eijkhout's TeX by topic (http://eijkhout.net/texbytopic/texbytopic.html), which is less fun to read but equally informative.