narrow-to-defun

narrow-to-defun is an interactive compiled Lisp function in `lisp.el'.

It is bound to C-x n d.

(narrow-to-defun &optional INCLUDE-COMMENTS)

Make text outside current defun invisible.
The current defun is the one that contains point or follows point.
Preceding comments are included if INCLUDE-COMMENTS is non-nil.
Interactively, the behavior depends on `narrow-to-defun-include-comments'.