19.2 Invoking Macros

After a macro is defined (see the previous section), you can use (invoke) it in your document like this:

     @macroname {arg1, arg2, ...}

and the result will be just as if you typed the body of macroname at that spot. For example:

     @macro foo {p, q}
     Together: \p\ & \q\.
     @end macro
     @foo{a, b}

produces:

     Together: a & b.

Thus, the arguments and parameters are separated by commas and delimited by braces; any whitespace after (but not before) a comma is ignored. The braces are required in the invocation (but not the definition), even when the macro takes no arguments, consistent with all other Texinfo commands. For example:

     @macro argless {}
     No arguments here.
     @end macro
     @argless{}

produces:

     No arguments here.

To insert a comma, brace, or backslash in an argument, prepend a backslash, as in

     @macname {\\\{\}\,}

which will pass the (almost certainly error-producing) argument `\{},' to macname. However, commas in parameters, even if escaped by a backslash, might cause trouble in TeX.

If the macro is defined to take a single argument, and is invoked without any braces, the entire rest of the line after the macro name is supplied as the argument. For example:

     @macro bar {p}
     Twice: \p\ & \p\.
     @end macro
     @bar aah

produces:

     Twice: aah & aah.

If the macro is defined to take a single argument, and is invoked with braces, the braced text is passed as the argument, regardless of commas. For example:

     @macro bar {p}
     Twice: \p\ & \p\.
     @end macro
     @bar{a,b}

produces:

     Twice: a,b & a,b.