Learning GNU Emacs, Second Edition

Marking up Text for T_EX and L_AT_EX

GNU Emacs provides much fuller support for marking up T_EX files than it does for troff files. Both T_EX and L_AT_EX modes are major modes; once you turn them on, all kinds of special behavior kicks in to help you mark up and process these files from within Emacs. Many of the features of T_EX mode also apply to L_AT_EX; users should read this section first, then go on to read about additional features of L_AT_EX mode.

To enter T_EX mode, type ESC x tex-mode RETURN. Emacs looks at the file to see if it looks like T_EX or L_AT_EX and puts you in the correct mode. If you want to specify T_EX mode particularly, type ESC x plain-tex-mode RETURN. Similarly, to start L_AT_EX mode, type ESC x latex-mode RETURN.

Matching Braces

T_EX commands often take the form \keyword{text}. T_EX mode doesn’t try to figure out if you’re using the “right” keywords, since T_EX is extensible and you may have defined your own keywords. It does, however, provide support for avoiding the most common T_EX error: mismatched curly braces and dollar signs.

In T_EX, curly braces ({}) and dollar signs ($$) should always appear in pairs; Emacs checks to make sure that each opening brace or dollar sign also has a counterpart. When you type a closing brace or dollar sign, the cursor moves quickly to its counterpart (provided that it is on the screen; it shows the context in the minibuffer if it is not), then back again. This visual check doesn’t actually affect the cursor’s location in the file; if ...