TeXStudio autocompletes environments. How can I get AUCTeX to do the same?

I can begin typing an environment name (say myenvironment) and, after entering a part of it (my, myenv, etc.), I hit Control-Alt-Space, and TeXStudio autocompletes the environment (asking if there are multiple possibilities), and sets the point between \begin{myenvironment} and \end{myenvironment}.

I tried yasnippet mode, but this works only for predefined snippets. So I have, for example, to define a keyword myenv and it will only autocomplete the snippet for the environment if myenv + TAB is entered and not when only my + TAB is entered (with a list of possible completions) or if I type myenvi + TAB.

I also tried predictive-mode which seems to complete only words.

EDIT: I know the AUCTeX way to do this via C-c C-e. The difference to the desired TeXStudio approach is that you have to give a key sequence first and then input a few letters of the environment name, whereas in TeXStudio it is the other way around (which is what I am asking here).

  • Both company-mode and auto-complete-mode offer integration for yasnippet, perhaps that's what you're looking for.
    – wasamasa
    Dec 21, 2014 at 23:24

4 Answers 4


Auctex provides environment completion with the function M-x LaTeX-environment by default bound to C-c C-e. The details are provided in the fine manual.

  • 1
    Thanks. But that's not exactly what I asked for. See my edit above.
    – student
    Dec 21, 2014 at 22:08

@Tyler's answer (C-c C-e) is the simplest and most straightforward way to get environments insofar as it's the built-in way to use AUCTeX's functionality. Since it gets you 99% of the way there, it seems like the way to go unless you really need to do it auto-complete style.

If you really wanted to, you could wrap that command in a snippet so that you could invoke it while typing (here, as ,env TAB):

# -*- mode: snippet -*-
# name: environment
# key: ,env
# type: command
# --
(call-interactively #'LaTeX-environment)

Of course, that's little more than a change of keybindings. (I use the snippet to minimize use of the Control key, but YMMV.) If, however, you're using ido-mode (and particularly ido-vertical-mode), it'll make the completion experience much more pleasant in either the stock (C-c C-e) or snippet version.


The command LaTeX-insert-environment-at-point defined below tries to complete an environment name at point. If the prefix is ambiguous, it pulls up the same list of completions as C-x C-e does. If AUCTeX knows about the environment, you may be prompted for parameters (same as with C-x C-e). As a bonus, if the name is preceded by a backslash, insert a command instead. Bind it to the key of your choice.

(defvar LaTeX-environment-name-characters
(defun LaTeX-insert-environment-at-point ()
  "Insert \begin{ENVIRONMENT}...\end{ENVIRONMENT}, completing the word at point.
If the word at point is preceded by a backslash, complete a macro name instead,
like \\[TeX-insert-macro].
The customization possibilities are the same as \\[LaTeX-environment]."
  (interactive "@*")
    (let* ((prefix-start (save-excursion
                           (skip-chars-backward LaTeX-environment-name-characters)
           (backslash (and (> prefix-start (point-min))
                           (= (char-after (1- prefix-start)) ?\\)))
           (completions (if backslash
           (prefix (buffer-substring-no-properties prefix-start (point)))
           (matches (remove-if-not (lambda (entry)
                                     (string-prefix-p prefix entry))
                                   (mapcar #'car completions)))
           (name (case (length matches)
                    (error "No environment name begins with %s" prefix))
                    (car matches))
                    ;; Gross hack: arrange to show the list of completions,
                    ;; by pushing a `minibuffer-complete' event (assuming
                    ;; default key bindings).
                    (setq unread-command-events (cons 'tab unread-command-events))
                    (completing-read (if backslash "Macro: "
                                       "Environment type: ")
                                     (if backslash
      (delete-region prefix-start (point))
      (funcall (if backslash #'TeX-insert-macro #'LaTeX-environment-menu) name))))
  • Thanks, I tried it but, I got the following error message: Mark set completing-read-default: Command attempted to use minibuffer while in minibuffer Quit [2 times] Mark set Mark saved where search started let*: Symbol's function definition is void: remove-if-not
    – student
    Dec 28, 2014 at 19:57

To get such behaviour, you an use helm-c-yasnippet. Using the command helm-yas-complete in you case, it will do exactly what you want: gives a list of candidates available in yasnippet that start with the supplied prefix.

By default, yasnippet is bundled with common snippets. You can load more snippets with yasnippets-latex.

  • Interesting. Would this not require you to have all of the snippets pre-defined, however?
    – Dan
    Dec 22, 2014 at 12:46
  • 1
    Yes. Here are the default predefined templates in yasnippet. At least you have all the standard environments. Maybe if someone creates helm-auctex-environment, then we will have something similar to helm-yas-complete without predefining templates.
    – Tu Do
    Dec 22, 2014 at 14:56

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