Setting outline-regexp automatically for a major mode

[uzibalqa <uzibalqa@proton.me>]

I have made a minor mode called tika that gets activated automatically for some
major modes. 

I use hooks for that

(defun tika-addhook ()
  "Activate minor-mode' automatically for specific major-modes."
  (add-hook 'emacs-lisp-mode-hook #'tika-minor-mode)
  (add-hook 'sh-mode-hook         #'tika-minor-mode)
  (add-hook 'f90-mode-hook        #'tika-minor-mode)
  (add-hook 'fortran-mode-hook    #'tika-minor-mode)
  (add-hook 'latex-mode-hook      #'tika-minor-mode)
  (add-hook 'plain-tex-mode-hook  #'tika-minor-mode))

This minor mode also sets the variables outline-regexp and outline-heading-alist
according to the specific major mode using the function tika-outlhg-regexp.  Which
I want to run automatically as soon as a file gets loaded.

Would one make hooks for the function like so, or do something else

(defun tika-addhook-hgptn ()
   (add-hook 'emacs-lisp-mode-hook #'tika-outlhg-regexp)
   (add-hook 'sh-mode-hook         #'tika-outlhg-regexp)
   (add-hook 'f90-mode-hook        #'tika-outlhg-regexp)
   (add-hook 'fortran-mode-hook    #'tika-outlhg-regexp)
   (add-hook 'latex-mode-hook      #'tika-outlhg-regexp)
   (add-hook 'plain-tex-mode-hook  #'tika-outlhg-regexp) )

When should tika-addhook-hgptn be called ?  I have been thinking 
of doing the following

  (require 'tika)
  (tika-addhook)
  (tika-addhook-hgptn)

Or is the above complicating a simple thing ?

This is the function setting outline-regexp and outline-heading-alist

(defun tika-outlhg-regexp ()

  (cond
    ((eq major-mode 'emacs-lisp-mode)
          (let ( (hrklevels tematika-elisp-hrklevels) )
            (setq outline-regexp
                  (concat (regexp-opt (mapcar 'car hrklevels)) "\\>"))
            (setq outline-heading-alist hrklevels)
            (setq-local outline-level 'outline-level)))

    ((eq major-mode 'sh-mode)
          (let ( (hrklevels tematika-bash-hrklevels) )
            (setq outline-regexp
                  (concat (regexp-opt (mapcar 'car hrklevels)) "\\>"))
            (setq outline-heading-alist hrklevels)))

    ((eq major-mode 'f90-mode)
          (let ( (hrklevels tematika-fortran-hrklevels) )
            (setq outline-regexp
                  (concat (regexp-opt (mapcar 'car hrklevels)) "\\>"))
            (setq outline-heading-alist hrklevels)))

    ((eq major-mode 'fortran-mode)
          (let ( (hrklevels tematika-f77-hrklevels) )
            (setq outline-regexp
                  (concat (regexp-opt (mapcar 'car hrklevels)) "\\>"))
            (setq outline-heading-alist hrklevels)))

    ((eq major-mode 'latex-mode)
          (let ( (hrklevels tematika-latex-hrklevels) )
            (setq outline-regexp
                  (concat (regexp-opt (mapcar 'car hrklevels)) "\\>"))
            (setq outline-heading-alist hrklevels)
            (setq-local outline-level 'outline-level)))

    ((eq major-mode 'plain-tex-mode)
          (let ( (hrklevels tematika-tex-hrklevels) )
            (setq outline-regexp
                  (concat (regexp-opt (mapcar 'car hrklevels)) "\\>"))
            (setq outline-heading-alist hrklevels))) ))

;; tematika-outlhg-regexp ends here