Persistent colors in an emacs text buffer - emacs

Question

After highlighting text in an emacs buffer using a regexp (1), it's easy enough to write the setting in the file (2), but I am missing a third step for persistence.
(1) Set
Doing M-s h r (highlight-regexp) and, say, \{.*\} followed by italic will highlight everything between curly braces in that style.
(2) Write
Subsequently calling C-x w b (hi-lock-write-interactive-patterns) will write the string
# Hi-lock: (("\\{.*\\}" (0 (quote italic) t)))
in the buffer, after asking for the comment string (I used #).
(3) Re-use
What is the third step needed to make this highlighting persistent, i.e., to make it survive saving/loading the file from disk?

Answer 1

If you C-h f hi-lock-write-interactive-pattern, you'll see in the help buffer a link to hi-lock.el. Often Lisp libraries have some usage information at the beginning of the file and it's handy to check.
In this case, it tells how to make it persistent:
;; To enable the use of patterns found in files (presumably placed
;; there by hi-lock) include the following in your init file:
;;
;; (setq hi-lock-file-patterns-policy 'ask)
;;
;; If you get tired of being asked each time a file is loaded replace
;; `ask' with a function that returns t if patterns should be read.

Answer 2

How about the possibility of creating a function that has a hook relating to the file you want to load -- e.g., a text-mode-hook or perhaps a specific file hook (if something like that exists)?
;; M-x ae-hi-lock-features
(global-hi-lock-mode 1)
(defface af-bold-yellow-box '((t (:background "black"
:foreground "yellow"
:underline "red"
:height 200
:bold t
))) "yellow-box-face")
(defun z-hi-lock-quizzes ()
;; this next line is necessary to correct sloppy hi-locking
(if (not hi-lock-mode)
(progn (hi-lock-mode -1)
(hi-lock-mode 1))
(hi-lock-mode)
(hi-lock-mode))
(highlight-regexp "^%-\\*-mode:LaTeX.*$" (quote hi-conceal-content));
(highlight-regexp "^%-#-(.+$" (quote hi-lock-page-break));
(highlight-regexp "food" (quote af-bold-yellow-box));
)
(defun ae-hi-lock-features ()
(interactive)
(z-hi-lock-quizzes)
;; ... call other functions ...
)
(add-hook 'text-mode-hook 'ae-hi-lock-features)

Answer 3

https://www.gnu.org/software/emacs/manual/html_node/emacs/Highlight-Interactively.html
C-x w i
Extract regexp/face pairs from comments in the current buffer (hi-lock-find-patterns).
Thus, you can enter patterns interactively
with highlight-regexp, store them into the file with
hi-lock-write-interactive-patterns, edit them (perhaps including
different faces for different parenthesized parts of the match), and
finally use this command (hi-lock-find-patterns) to have Hi Lock
highlight the edited patterns.