Add read-only 'markdown-ts-view-mode' (bug#81023)

This new derived mode is intended for consumers that render
Markdown content for display rather than editing, such as Eglot
and Eldoc when showing documentation popups and buffers.  It
pre-sets the relevant customizations (markup hidden, inline
images on, hard-line-break markup hidden, native code-block
fontification, table and code-block context minor modes off),
makes the buffer read-only, and uses its own keymap derived from
'special-mode-map' so navigation keys behave like a viewer.

A pre-init hook lets callers normalize buffer content before the
grammar parses it; 'markdown-ts-add-final-newline' is the
default so that markup depending on a terminating newline parses
correctly.  'markdown-ts-buffer-string' returns the rendered
buffer string with overlay faces flattened into text properties,
which is useful for callers that capture the rendered output.

Along the way: 'list_marker_parenthesis' is now recognized as an
ordered list marker; the strikethrough query is simplified to a
single rule; thematic breaks span the window via an ':extend'
underline when the face supports it.

* lisp/textmodes/markdown-ts-mode.el (markdown-ts-view-mode):
New read-only derived mode.
(markdown-ts-view-mode-map): New keymap.
(markdown-ts-view-mode-pre-init-hook): New hook, defaulting to
'markdown-ts-add-final-newline'.
(markdown-ts-mode--initialize): New helper, factored out of
'markdown-ts-mode' so 'markdown-ts-view-mode' can reuse the
parser readiness and setup logic after overriding local
variables.
(markdown-ts-mode): Call 'markdown-ts-mode--initialize'.
(markdown-ts-add-final-newline): New function.
(markdown-ts-buffer-string): New function.
(markdown-ts-unordered-list-marker): New defcustom.
(markdown-ts-hard-line-break-backslash)
(markdown-ts-hard-line-break-space): Accept the symbol 'hide.
(markdown-ts--fontify-hard-line-break): Honor 'hide.
(markdown-ts--fontify-atx-heading)
(markdown-ts--fontify-setext-heading)
(markdown-ts--fontify-atx-delimiter)
(markdown-ts--fontify-unordered-list-marker)
(markdown-ts--list-item-depth): New functions supporting clean
rendering when markup is hidden.
(markdown-ts--fontify-thematic-break): Use ':extend' underline
span when the face supports it.
(markdown-ts--resolve-display-value): Accept non-cons values.
(markdown-ts--list-ordered-item-p): Also recognize
'list_marker_parenthesis'.
(markdown-ts--range-settings): Mark markdown-inline embed as
':local t'.
(markdown-ts--set-up): Create the markdown-inline parser only in
the inline setup branch; drop the redundant
'markdown-ts-hide-markup' make-local-variable.
(markdown-ts--treesit-settings): Route atx and setext headings
to their dedicated fontifiers; route unordered list markers
through 'markdown-ts--fontify-unordered-list-marker'; move
'strikethrough' to the simpler paragraph-inline query.

0 files changed, 0 insertions, 0 deletions