19.5 `definfoenclose': Customized Highlighting

A @definfoenclose command may be used to define a highlighting command for Info, but not for TeX. A command defined using @definfoenclose marks text by enclosing it in strings that precede and follow the text. You can use this to get closer control of your Info output.

Presumably, if you define a command with @definfoenclose for Info, you will create a corresponding command for TeX, either in texinfo.tex, texinfo.cnf, or within an `@iftex' in your document.

Write a @definfoenclose command on a line and follow it with three arguments separated by commas. The first argument to @definfoenclose is the @-command name (without the @); the second argument is the Info start delimiter string; and the third argument is the Info end delimiter string. The latter two arguments enclose the highlighted text in the Info file. A delimiter string may contain spaces. Neither the start nor end delimiter is required. If you do not want a start delimiter but do want an end delimiter, you must follow the command name with two commas in a row; otherwise, the Info formatting commands will naturally misinterpret the end delimiter string you intended as the start delimiter string.

If you do a @definfoenclose on the name of a pre-defined macro (such as @emph, @strong, @t, or @i), the enclosure definition will override the built-in definition.

An enclosure command defined this way takes one argument in braces; this is intended for new markup commands (see Marking Text).

For example, you can write:

     @definfoenclose phoo,//,\\

near the beginning of a Texinfo file to define @phoo as an Info formatting command that inserts `//' before and `\\' after the argument to @phoo. You can then write @phoo{bar} wherever you want `//bar\\' highlighted in Info.

Also, for TeX formatting, you could write

     @iftex
     @global@let@phoo=@i
     @end iftex

to define @phoo as a command that causes TeX to typeset the argument to @phoo in italics.

Each definition applies to its own formatter: one for TeX, the other for texinfo-format-buffer or texinfo-format-region. The @definfoenclose command need not be within `@ifinfo', but the raw TeX commands do need to be in `@iftex'.

Here is another example: write

     @definfoenclose headword, , :

near the beginning of the file, to define @headword as an Info formatting command that inserts nothing before and a colon after the argument to @headword.

`@definfoenclose' definitions must not be recursive, directly or indirectly.