From e4731375eaf622df0187d47d949fb9f4e53330be Mon Sep 17 00:00:00 2001
From: Alan Schmitt <alan.schmitt@polytechnique.org>
Date: Wed, 25 Nov 2015 08:48:58 +0100
Subject: [PATCH] ox-latex: Extend custom-lang-environments

* lisp/ox-latex.el (org-latex-custom-lang-environments): extend the
  documentation string.
* lisp/ox-latex.el (org-latex-src-block): allow a custom language
  environment to be a format string to be directly inserted.
---
 lisp/ox-latex.el | 50 ++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 40 insertions(+), 10 deletions(-)

diff --git a/lisp/ox-latex.el b/lisp/ox-latex.el
index bbf7f41..1b0bff5 100644
--- a/lisp/ox-latex.el
+++ b/lisp/ox-latex.el
@@ -1025,17 +1025,40 @@ block-specific options, you may use the following syntax:
   "Alist mapping languages to language-specific LaTeX environments.
 
 It is used during export of src blocks by the listings and minted
-latex packages.  For example,
+latex packages.  The environment may either be a simple string,
+composed of only letters and numbers.  In this case, the string is
+directly the name of the latex environment to use.  The environment
+may also be a format string.  In this case the format string will be
+directly exported.  This format string may contain these elements:
+
+  %c for the formatted source
+  %C for the caption
+  %f for the float attribute
+  %l for an appropriate label 
+
+For example,
 
   (setq org-latex-custom-lang-environments
-     '((python \"pythoncode\")))
+     '((python \"pythoncode\")
+       (ocaml \"\\\\begin{listing}\\n\\\\begin{minted}{ocaml}%c\\\\end{minted}\\n\\\\caption{%C}\\n\\\\label{%l}\")))
 
 would have the effect that if org encounters begin_src python
 during latex export it will output
 
   \\begin{pythoncode}
   <src block body>
-  \\end{pythoncode}")
+  \\end{pythoncode}
+
+and if org encounters begin_src ocaml during latex export it will
+output
+
+  \\begin{listing}
+  \\begin{minted}{ocaml}
+  <src block body>
+  \\end{minted}
+  \\caption{<caption>}
+  \\label{<label>}
+  \\end{listing}")
 
 
 ;;;; Compilation
@@ -2756,13 +2779,20 @@ contextual information."
 			   (org-export-format-code-default src-block info))))))
        ;; Case 2.  Custom environment.
        (custom-env
-	(let ((caption-str (org-latex--caption/label-string src-block info)))
-	  (format "\\begin{%s}\n%s\\end{%s}\n"
-		  custom-env
-		  (concat (and caption-above-p caption-str)
-			  (org-export-format-code-default src-block info)
-			  (and (not caption-above-p) caption-str))
-		  custom-env)))
+	(let ((caption-str (org-latex--caption/label-string src-block info))
+              (formatted-src (org-export-format-code-default src-block info)))
+          (if (string-match-p "\\`[a-zA-Z0-9]+\\'" custom-env)
+	      (format "\\begin{%s}\n%s\\end{%s}\n"
+		      custom-env
+		      (concat (and caption-above-p caption-str)
+			      formatted-src
+			      (and (not caption-above-p) caption-str))
+		      custom-env)
+	    (format-spec custom-env
+			 `((?c . ,formatted-src)
+			   (?C . ,caption)
+			   (?f . ,float)
+			   (?l . ,(org-latex--label src-block info)))))))
        ;; Case 3.  Use minted package.
        ((eq listings 'minted)
 	(let* ((caption-str (org-latex--caption/label-string src-block info))
-- 
2.6.3