From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Reza Nikoopour <rnikoopour@gmail.com>
Cc: emacs-devel@gnu.org
Subject: Re: Help Understanding syntax-propertize-function
Date: Mon, 15 Mar 2021 19:30:08 -0400 [thread overview]
Message-ID: <jwvblbkrofw.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <CAKesZq3e0WZ50yFWtDfgfHNT1dtO0hwsYtewXQ+o-0Wh76xoMA@mail.gmail.com> (Reza Nikoopour's message of "Mon, 15 Mar 2021 15:48:13 -0700")
> Could someone help explain the following code:
I'm not sure which part you don't understand, so I'll stick to
generic ideas:
> (defun hcl--syntax-propertize-function (start end)
> (goto-char start)
> (hcl--syntax-propertize-heredoc end)
> (funcall
> (syntax-propertize-rules
> (hcl--here-doc-beg-re
> (2 (hcl--font-lock-open-heredoc
> (match-beginning 0) (match-string 1) (match-beginning 2))))
> ("\\s|" (0 (prog1 nil (hcl--syntax-propertize-heredoc end)))))
> (point) end))
Since we don't know where `start` will be, it can be within a heredoc.
So we first call `hcl--syntax-propertize-heredoc` which should detect
when we're inside a heredoc and if so process it until its end and if not
do nothing.
Once that's done, we know we're not in a heredoc, hence we're in
"normal code" and we then use `syntax-propertize-rules` to try and
detect a few interesting conditions. One of them is when we find
a match for `hcl--here-doc-beg-re`, in that case we call
`hcl--font-lock-open-heredoc` to place some syntactic marker at the
beginning of the heredoc. The other is when we see a char of
syntactic category `|`, which doesn't occur in the wild but should
presumably be the result of `hcl--font-lock-open-heredoc` having placed
it there, so it announces the beginning of a heredoc, in which case we
can call `hcl--syntax-propertize-heredoc` to process it.
Stefan
next prev parent reply other threads:[~2021-03-15 23:30 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-15 22:48 Help Understanding syntax-propertize-function Reza Nikoopour
2021-03-15 23:30 ` Stefan Monnier [this message]
2021-03-15 23:58 ` Reza Nikoopour
2021-03-16 1:42 ` Stefan Monnier
2021-03-16 15:37 ` Reza Nikoopour
2021-03-16 17:29 ` Stefan Monnier
2021-03-16 17:50 ` Reza Nikoopour
2021-03-24 20:29 ` Filipp Gunbin
2021-03-24 22:10 ` Stefan Monnier
2021-03-24 22:54 ` Filipp Gunbin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=jwvblbkrofw.fsf-monnier+emacs@gnu.org \
--to=monnier@iro.umontreal.ca \
--cc=emacs-devel@gnu.org \
--cc=rnikoopour@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).