Folding yaml by markers

Folding yaml by markers

[Hartmut Goebel]

Hello,

I have to deal with some YAML documents, which use some kind of
"literate programming": The comments contain documentation for the
values. These files already contain fold markers `[[[` and `]]]`
provided by the mainterner (who uses vim).

I want to leverage these fold markers for emacs, by adjusting
hs-special-modes-alist, but did not manage.  The blocks are folded by
yaml-structure, not by fold marks.

Any idea how do I need to set hs-special-modes-alist?

Here is my code:

 (defvar hs-special-modes-alist
   (mapcar 'purecopy
    '((yaml-mode "[[[" "#\s+]]]" nil))))

And here is an example document:

---
# Heading/Folding structure in this document
# * Variables
# ** PostgreSQL installation, packages
# *** .. envvar:: postgresql__upstream
# *** .. envvar:: postgresql__upstream_key_id
# *** pg_wrapper integration
# *** .. envvar:: postgresql__default_database
#

# Variables [[[
# =======================================

# PostgreSQL installation, packages [[[
# -------------------------------------

# .. envvar:: postgresql__upstream [[[
#
# Enable PostgreSQL Global Developmet Group APT repository?
# More information: https://wiki.postgresql.org/wiki/Apt
postgresql__upstream: False

                                                                   # ]]]
# .. envvar:: postgresql__upstream_key_id [[[
#
# The GPG fingerprint of the upstream APT repository key.
postgresql__upstream_key_id: 'B97B0AFCAA1A47F044F244A07FCC7D46ACCC4CF8'
                                                                   # ]]]
                                                                   # ]]]
# pg_wrapper integration [[[
# --------------------------

# .. envvar:: postgresql__default_database [[[
#
# Name of the database the users should connect to, set as default in
# :file:`/etc/postgresql-common/user_clusters`. If the name is ``*``,
users will
# connect to the database with the same name as their login.
postgresql__default_database: '*'

                                                                   # ]]]
                                                                   # ]]]
                                                                   # ]]]

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |

Re: Folding yaml by markers

[Robert Pluim]

>>>>> On Fri, 11 Oct 2019 16:41:07 +0200, Hartmut Goebel <h.goebel@crazy-compilers.com> said:

    Hartmut> Hello,
    Hartmut> I have to deal with some YAML documents, which use some kind of
    Hartmut> "literate programming": The comments contain documentation for the
    Hartmut> values. These files already contain fold markers `[[[` and `]]]`
    Hartmut> provided by the mainterner (who uses vim).

    Hartmut> I want to leverage these fold markers for emacs, by adjusting
    Hartmut> hs-special-modes-alist, but did not manage.  The blocks are folded by
    Hartmut> yaml-structure, not by fold marks.

    Hartmut> Any idea how do I need to set hs-special-modes-alist?

    Hartmut> Here is my code:

    Hartmut>  (defvar hs-special-modes-alist
    Hartmut>    (mapcar 'purecopy
    Hartmut>     '((yaml-mode "[[[" "#\s+]]]" nil))))

You probably want to use 'setq' rather than 'defvar'.

Robert

Re: Folding yaml by markers

[Hartmut Goebel]

Am 14.10.19 um 15:02 schrieb Robert Pluim:
>     Hartmut>  (defvar hs-special-modes-alist
>     Hartmut>    (mapcar 'purecopy
>     Hartmut>     '((yaml-mode "[[[" "#\s+]]]" nil))))
>
> You probably want to use 'setq' rather than 'defvar'.

Thanks for pointing to this. Anway this does not seem to be the relevant
issue. I (being an elisp newbie) learned about M-: and added the value
manually. Now I'm one step further: Using

(add-to-list 'hs-special-modes-alist '(yaml-mode "\\[\\[\\[" "\\]\\]\\]"
"xxxx" nil nil))

I was able to add an appropriate entry to hs-special-modes-alist.

Using this expression, I was able to make hs-minor-mode fold, BUT ONLY
if the brackets are not part of a yaml comment. Which makes me curious!

If I understand the code (line 672 in hideshow.el) correctly,
`hs-c-start-regex` is st ot the 3rd paramater ("xxxx"), which is
documented to be a regex for starting a comment. Thus "xxxx" should
defacto disable comment detection. Yet comments are still considered.

Any hints on this?

The documentation for hs-special-modes-alist is at
<https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/progmodes/hideshow.el#n268>
and the relevant function `|hs-grok-mode-type`|||at
<https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/progmodes/hideshow.el#n654>.


-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |