highlight-indentation by AntonJohansson is a function made to show vertical guide lines of indentation levels (spaces only). The code is available at:
Appearance of guidelines is customizable by changing the face
‘highlight-indent-face’. By default,
‘highlight-indent-face’ inherits from
‘fringe’, which in most color-themes has an unobtrusive color.
This looks really neat. Is there a way to extend it to work with Lisp code? Something like the following:
(if n | (let ((m 0) (p list)) | | (while (consp p) | | | (setq m (1+ m) | | | | p (cdr p))) | | (if (<= n 0) p | | | (if (< n m) | | | | (nthcdr (- m n) list) | | | | list))) | (while (consp (cdr list)) | | (setq list (cdr list))) | list)
It would really improve the readability of long
if forms like above (this is taken from the definition of
subr.el). – VegardOye
In its current form, the actual functionality of
‘highlight-indentation’ is very trivial: font-lock a space character followed by a fixed amount of space characters. So for it to work with lisp’s variable indentation some major changes are needed… – AntonJohansson
That link to ran9er’s GitHub repo seemed to have moved to indent-hint.el.
For a more complex approach, see highlight-indent-guides