(asdf:component-name-to-pathname-components s &key force-directory
|Function: Splits the path string S, returning three values: A flag that is either :absolute or :relative, indicating how the rest of the values are to be interpreted. A directory path --- a list of strings, suitable for use with MAKE-PATHNAME when prepended with the flag value. A filename with type extension, possibly NIL in the case of a directory pathname. FORCE-DIRECTORY forces S to be interpreted as a directory pathname (third return value will be NIL, final component of S will be treated as part of the directory path. The intention of this function is to support structured component names, e.g., (:file "foo/bar"), which will be unpacked to relative pathnames.