Add LaTeX narrowing functions

1 files changed, 46 insertions, 0 deletions

diff --git a/lisp/init-tex.el b/lisp/init-tex.el
index 10539c0..b2f4d0f 100644
--- a/lisp/init-tex.el
+++ b/lisp/init-tex.el
@@ -15,4 +15,50 @@
 
 (setq reftex-default-bibliography '("~/refs/refs.bib"))
 
+(defun km/latex-narrow-to-single-tag (&optional tag)
+  "Narrow region to LaTeX tag.
+This is meant for single elements, like \"\\section\". If TAG is
+not given, it is taken from the active region."
+  (interactive)
+  (save-excursion
+    (let* ((tag (or tag
+                (buffer-substring-no-properties (mark) (point))))
+           (tag (if (s-starts-with? "\\" tag)
+                    tag
+                  (concat "\\" tag)))
+           (beg (progn (end-of-line)
+                       (search-backward tag)))
+           (end (progn (forward-line 1)
+                       (unless (search-forward tag nil t)
+                         (search-forward "\\end{document}"))
+                       (forward-line -1)
+                       (point))))
+      (narrow-to-region beg end))))
+
+(defun km/latex-narrow-to-paired-tag (&optional tag)
+  "Narrow region to LaTeX tag.
+This is meant for paired, like \"\\begin{document}\". If TAG is
+not given, it is taken from the active region."
+  (interactive)
+  (save-excursion
+    (let* ((tag (or tag
+                (buffer-substring-no-properties (mark) (point))))
+           (beg (progn (end-of-line)
+                       (search-backward (format "\\begin{%s}" tag))))
+           (end (progn (forward-line 1)
+                       (search-forward (format "\\end{%s}" tag)))))
+      (narrow-to-region beg end))))
+
+(defun km/latex-narrow-to-document ()
+  "Narrow region to LaTeX document text.
+The point should be beyond \"\\begin{document}\"."
+  (interactive)
+  (km/latex-narrow-to-paired-tag "document"))
+
+(defun km/latex-narrow-to-section ()
+  "Narrow region to current LaTeX section.
+The point should be beyond \"\\section\"."
+  (interactive)
+  (km/latex-narrow-to-single-tag "section"))
+
 (provide 'init-tex)