Within a macro definition, you can use the
(see Defining Macros) to specify how TAB should indent
calls to the macro. An indentation specification is written like this:
(declare (indent indent-spec))
Here are the possibilities for indent-spec:
This is the same as no property—use the standard indentation pattern.
Handle this function like a ‘def’ construct: treat the second line as the start of a body.
The first number arguments of the function are
distinguished arguments; the rest are considered the body
of the expression. A line in the expression is indented according to
whether the first argument on it is distinguished or not. If the
argument is part of the body, the line is indented
more columns than the open-parenthesis starting the containing
expression. If the argument is distinguished and is either the first
or second argument, it is indented twice that many extra columns.
If the argument is distinguished and not the first or second argument,
the line uses the standard pattern.
symbol should be a function name; that function is called to calculate the indentation of a line within this expression. The function receives two arguments:
The position at which the line being indented begins.
The value returned by
parse-partial-sexp (a Lisp primitive for
indentation and nesting computation) when it parses up to the
beginning of this line.
It should return either a number, which is the number of columns of indentation for that line, or a list whose car is such a number. The difference between returning a number and returning a list is that a number says that all following lines at the same nesting level should be indented just like this one; a list says that following lines might call for different indentations. This makes a difference when the indentation is being computed by C-M-q; if the value is a number, C-M-q need not recalculate indentation for the following lines until the end of the list.