31.2 Predicates on Markers

You can test an object to see whether it is a marker, or whether it is either an integer or a marker. The latter test is useful in connection with the arithmetic functions that work with both markers and integers.

function markerp object

This function returns t if object is a marker, nil otherwise. Note that integers are not markers, even though many functions will accept either a marker or an integer.

function integer-or-marker-p object

This function returns t if object is an integer or a marker, nil otherwise.

function number-or-marker-p object

This function returns t if object is a number (either integer or floating point) or a marker, nil otherwise.