Not exactly the world's most pressing problem, but one that has now exceeded my tolerance level. If I comment out a line of input such as


with Alt-/ (Windows), I get


But, as a believer in typographical as well as programmatic neatness what I really want is...

(* f[x_]:=x+1; *)

Just a space after the opening and before the closing...

How can that be done? Or would it spoil some vast eternal plan...?

  • $\begingroup$ Hi Julian, maybe it's too simple what I want to ask, but how do you (un)comment with the keyboard? "Alt+/" doesn't seem to work... which keys do you press exactly? $\endgroup$ Jan 7 '19 at 9:56
  • $\begingroup$ @Anoldmaninthesea.Alt+/ has always worked for me (MMA 9-, Windows) but care must be taken to ensure that the opening and closing brackets of (* *) are the 1st and last characters of the selection before typing Alt+/, otherwise MMA will not recognise the selection as a comment; I often end up re-commenting comments rather than uncommenting them for this very reason. $\endgroup$ Jan 8 '19 at 19:05

New answer:

I updated my package to support not only templates but a menu with arbitrary actions so making an un/comment shortcut should be easier now.

Follow those steps:

  1. Install/update DevTools` v0.10.0+

  2. Actions are available in DevPackageDark.nb stylesheet but you can make them work in any notebook by:

    Needs @ "DevTools`";
       (*Keep in mind it hijacks "Ctrl+," which stands for NewColumn *)
  3. Open user actions file with EditNotebookActions[]

  4. Put there a new item:

    <|"Label" -> "Un/Comment", 
      "ShortKey" -> "c", 
      "Action" :> Module[{foo, nb = EvaluationNotebook[]},
        foo[RowBox[{"(*", " ".., content_, " ".., "*)"}]]:=NotebookWrite[
          nb, content, All
        foo[RowBox[{"(*",  content_, "*)"}]]:=FE`toggleComment[];
        foo[boxes_]:= NotebookWrite[
          nb, RowBox[{"(*", " ",boxes, " ", "*)"}], All
        foo @ CurrentValue[nb, "SelectionData"]
  5. Click 'Save&Test'

  6. You are ready to go with Ctrl+, (NewColumn hijacked) followed by c

enter image description here


You can use LiveTemplates Live code templates.

  • Go to a toolbar menu CodeTemplates > Edit User templates
  • Add a new template:

    <|"Label" -> "(* ... *)", "Template" -> "(* `sel` *)", "ShortKey" -> "c"|>
  • Save changes

  • Use it with ctrl+1 followed by c

enter image description here

Alternatively you can create a palette with something like this:

, NotebookApply[InputNotebook[]
  , RowBox[{"(*", RowBox[{" ", "\[SelectionPlaceholder]", " "}], "*)"}]

Or try to edit KeyEvenTranslations.tr file. Search around for guidelines but I find this method the least user friendly.

  • $\begingroup$ I now have devtools and some interesting extra capabilities to explore. I was reluctant to go that route at first, but I messed up the KeyEventTranslations.tr edits... I'll see if I can work out how to remove this nicer bracket pair using your tools... MMA's "uncomment" of course leaves the extra spaces :) Thank you. $\endgroup$ Oct 25 '18 at 19:16
  • $\begingroup$ @JulianMoore Yes, it is tricky with .tr files. I will appreciate any feedback you have on DevTools, don't hesitate to create github issues or comment here. I am planning to add a similar feature but only with simple procedures you'd like to keep in a menu. Currently it is dedicated to applying templates so it may be quite tricky to abuse it to 'uncomment'. $\endgroup$
    – Kuba
    Oct 25 '18 at 19:37
  • $\begingroup$ @JulianMoore Please see the edit. $\endgroup$
    – Kuba
    Nov 28 '18 at 7:57
  • $\begingroup$ thx will check it out this w/e $\endgroup$ Nov 30 '18 at 12:10
  • 1
    $\begingroup$ Is it possible to use DevTools without having to use the dark mode you implement? (Contrary to what many programmers seem to prefer, these old eyes of mine find black text on a white, or light, background, much easier to use.) $\endgroup$
    – murray
    Nov 30 '18 at 20:14

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