+(defun org-babel-tangle-single-block
+ (block-counter &optional only-this-block)
+ "Collect the tangled source for current block.
+Return the list of block attributes needed by
+`org-babel-tangle-collect-blocks'.
+When ONLY-THIS-BLOCK is non-nil, return the full association
+list to be used by `org-babel-tangle' directly."
+ (let* ((info (org-babel-get-src-block-info))
+ (start-line
+ (save-restriction (widen)
+ (+ 1 (line-number-at-pos (point)))))
+ (file (buffer-file-name))
+ (src-lang (nth 0 info))
+ (params (nth 2 info))
+ (extra (nth 3 info))
+ (cref-fmt (or (and (string-match "-l \"\\(.+\\)\"" extra)
+ (match-string 1 extra))
+ org-coderef-label-format))
+ (link (let ((link (org-no-properties
+ (org-store-link nil))))
+ (and (string-match org-bracket-link-regexp link)
+ (match-string 1 link))))
+ (source-name
+ (intern (or (nth 4 info)
+ (format "%s:%d"
+ (or (ignore-errors (nth 4 (org-heading-components)))
+ "No heading")
+ block-counter))))
+ (expand-cmd
+ (intern (concat "org-babel-expand-body:" src-lang)))
+ (assignments-cmd
+ (intern (concat "org-babel-variable-assignments:" src-lang)))
+ (body
+ ;; Run the tangle-body-hook.
+ (let* ((body ;; Expand the body in language specific manner.
+ (if (org-babel-noweb-p params :tangle)
+ (org-babel-expand-noweb-references info)
+ (nth 1 info)))
+ (body
+ (if (assoc :no-expand params)
+ body
+ (if (fboundp expand-cmd)
+ (funcall expand-cmd body params)
+ (org-babel-expand-body:generic
+ body params
+ (and (fboundp assignments-cmd)
+ (funcall assignments-cmd params)))))))
+ (with-temp-buffer
+ (insert body)
+ (when (string-match "-r" extra)
+ (goto-char (point-min))
+ (while (re-search-forward
+ (replace-regexp-in-string "%s" ".+" cref-fmt) nil t)
+ (replace-match "")))
+ (run-hooks 'org-babel-tangle-body-hook)
+ (buffer-string))))
+ (comment
+ (when (or (string= "both" (cdr (assoc :comments params)))
+ (string= "org" (cdr (assoc :comments params))))
+ ;; From the previous heading or code-block end
+ (funcall
+ org-babel-process-comment-text
+ (buffer-substring
+ (max (condition-case nil
+ (save-excursion
+ (org-back-to-heading t) ; Sets match data
+ (match-end 0))
+ (error (point-min)))
+ (save-excursion
+ (if (re-search-backward
+ org-babel-src-block-regexp nil t)
+ (match-end 0)
+ (point-min))))
+ (point)))))
+ (result
+ (list start-line file link source-name params body comment)))
+ (if only-this-block
+ (list (cons src-lang (list result)))
+ result)))
+