Hi Nicolas,
So, I've now fixed the handling of already-$-delaminated fragments, and
removed the $$ from around environments.
Sorry to complicate things, but, looking at what the HTML fallback
actually is, I've had some further thoughts. The HTML backend will
either leave the content as-is, run `org-latex-to-html-convert-command',
or run something from `org-preview-latex-process-alist' and include an
<img>.
Should one want to convert LaTeX images say to an SVG for HTML export, I
do not think one would want this behaviour to also apply to LaTeX being
exported to markdown.
As such I see two 'sensible' paths forward: (1) just include LaTeX
verbatim when :with-latex is non-nil, or (2) introduce
`org-markdown-with-latex' which can be set to t/'verbatim or 'html.
In the attached patch, I've taken the first approach. Let me know if
you'd like to take the second approach, or just inherit the HTML
behaviour for LaTeX after all.
--
Timothy
>From a02dbcb21dddb6d9239d13308a78a45738d9b7e6 Mon Sep 17 00:00:00 2001
From: Timothy <tecos...@gmail.com>
Date: Thu, 1 Apr 2021 00:41:29 +0800
Subject: [PATCH] ox-md: Use TeX-style $ math wrapping
* lisp/ox-md.el (org-md-latex-environment, org-md-latex-fragment):
These two new filters wrap LaTeX maths in $ / $$ TeX-style notation.
While ox-md endeavours to adhere to the original Markdown specification,
and not any particular variant, the original specification does not deal
with LaTeX fragments at all, and so this change does not reduce how
faithfully the original specification is followed.
There is a major upside to this though. Of the many Markdown variants
that have emerged, those that support LaTeX very often exclusively
support TeX style notation. This change thus improves the utility of
the Markdown export for many use cases, and deviates no more from the
original specification that the current method.
---
lisp/ox-md.el | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/lisp/ox-md.el b/lisp/ox-md.el
index b6b2c1728..1ae0cf2d9 100644
--- a/lisp/ox-md.el
+++ b/lisp/ox-md.el
@@ -100,6 +100,8 @@ (org-export-define-derived-backend 'md 'html
(italic . org-md-italic)
(item . org-md-item)
(keyword . org-md-keyword)
+ (latex-environment . org-md-latex-environment)
+ (latex-fragment . org-md-latex-fragment)
(line-break . org-md-line-break)
(link . org-md-link)
(node-property . org-md-node-property)
@@ -460,6 +462,35 @@ (defun org-md-keyword (keyword contents info)
(_ (org-export-with-backend 'html keyword contents info))))
+;;;; Latex Environment
+
+(defun org-md-latex-environment (latex-environment contents info)
+ "Transcode a LATEX-ENVIRONMENT object from Org to Markdown.
+CONTENTS is nil. INFO is a plist holding contextual information."
+ (when (plist-get info :with-latex)
+ (let ((latex-frag (org-remove-indentation
+ (org-element-property :value latex-environment)))
+ (label (org-html--reference latex-environment info t)))
+ (if (org-string-nw-p label)
+ (replace-regexp-in-string "\\`.*"
+ (format "\\&\n\\\\label{%s}" label)
+ latex-frag)
+ latex-frag))))
+
+;;;; Latex Fragment
+
+(defun org-md-latex-fragment (latex-fragment contents info)
+ "Transcode a LATEX-FRAGMENT object from Org to Markdown.
+CONTENTS is nil. INFO is a plist holding contextual information."
+ (when (plist-get info :with-latex)
+ (let ((frag (org-element-property :value latex-fragment)))
+ (cond
+ ((string-match-p "^\\\\(" frag)
+ (concat "$" (substring frag 2 -2) "$"))
+ ((string-match-p "^\\\\\\[" frag)
+ (concat "$$" (substring frag 2 -2) "$$"))
+ (t frag))))) ; either already $-deliminated or a macro
+
;;;; Line Break
(defun org-md-line-break (_line-break _contents _info)
--
2.31.1
