#!/bin/sh
usage()
{
  printf 'usage: %s [file.lisp]\n' $0
  exit 1
}
## The first program finds certain definitions and inserts a new blank
## line *before* the definition.  Such action makes function
## definitions separated by two blank lines in some cases.  We then
## remove the excess with the second program.  Notice we need the -E
## option because we're using the | metacharacter that is only
## supported by popular sed programs with the -E option.  This
## violates POSIX sed, but keep in mind that we only run this when
## releasing the package.  This is a building tool, not part of the
## service.
sed -E '/^\(defun |\(defmacro /{
 i\

}' "$@" | sed '/^[ \t]*$/{
   N
   /^[ \t]*\n$/D
}'
## We first find a blank line.  Then we say N to expand the pattern
## space to include the next line.  Then we delete the *first* blank
## line and not the second---that's what the D command does.  This
## strategy is explained by Dale Dougherty and Arnold Robbins in ``sed
## & awk'' second edition, pages 112--114.