(defun delete-horizontal-space (&optional backward-only)
"Delete all spaces and tabs around point.
-If BACKWARD-ONLY is non-nil, delete them only before point."
+If BACKWARD-ONLY is non-nil (interactively, the prefix argument), delete
+them only before point."
(interactive "*P")
(delete-space--internal " \t" backward-only))
(defun just-one-space (&optional n)
"Delete all spaces and tabs around point, leaving one space (or N spaces).
+Interactively, N is the prefix numeric argument.
If N is negative, delete newlines as well, leaving -N spaces.
See also `cycle-spacing'."
(interactive "*p")