Type a sequence of subscript/superscript characters

[linwaytin]

When I use the REPL, I can type c\_max and hit TAB to get cₘₐₓ. This is super convenient. In emacs, I have to type them one by one, \_m TAB, \_a \TAB, and finally \_x TAB.

Is it possible to implement the same functionality in emacs?

[tpapp]

Everything is possible in Emacs, it just may not be convenient. Let's revisit this after we merge #100.

[niv-l]

Hi, any updates on this?

[tpapp]

Maybe I can implement it as an option in julia-latexsub-or-indent.

[9viz]

Having found this lacking myself, I came up with the following patch which seems to work in my limited testing.

diff --git a/julia-mode.el b/julia-mode.el
index 9e2c120..fb2f59a 100644
--- a/julia-mode.el
+++ b/julia-mode.el
@@ -791,18 +791,30 @@ (defun julia-latexsub ()
   "Perform a LaTeX-like Unicode symbol substitution."
   (interactive "*i")
   (let ((orig-pt (point)))
-    (while (not (or (bobp) (= ?\\ (char-before))
-		    (= ?\s (char-syntax (char-before)))))
-      (backward-char))
+    (skip-chars-backward "^[:space:]\\\\")
     (if (and (not (bobp)) (= ?\\ (char-before)))
-        (progn
-          (backward-char)
-          (let ((sub (gethash (buffer-substring (point) orig-pt) julia-mode-latexsubs)))
-            (if sub
-                (progn
-                  (delete-region (point) orig-pt)
-                  (insert sub))
-              (goto-char orig-pt))))
+        (let ((sub (gethash (buffer-substring (1- (point)) orig-pt) julia-mode-latexsubs)))
+          (if (null sub)
+              (if (memq (char-after) '(?_ ?^))
+                (let ((ss (string (char-after)))
+                      (all-avail t)
+                      repl r)
+                  (save-excursion
+                    (forward-char)      ; Skip over _/^.
+                    (while (and all-avail (< (point) orig-pt))
+                      (if (setq r (gethash (concat "\\" ss (string (char-after)))
+                                           julia-mode-latexsubs))
+                          (progn
+                            (setq repl (concat repl r))
+                            (forward-char))
+                        (setq all-avail nil))))
+                  (if (or (null all-avail) (null repl))
+                      (goto-char orig-pt)
+                    (delete-region (1- (point)) orig-pt)
+                    (insert repl)))
+              (goto-char orig-pt))
+            (delete-region (1- (point)) orig-pt)
+            (insert sub)))
       (goto-char orig-pt))))
 
 (defun julia-latexsub-or-indent (arg)