[Interest] Preventing ^2 from being converted to a superscript 2

[Jean-Michaël Celerier]

It really is a X11 / xkb feature of the normal fr keymaps.
They'd have the same result in every other app.
Both typing ^ + space and ^ twice allow getting a single "^", I think
that's something you have to learn as a french linux user as it's a long default
and every azerty keymap variant does it to the great confusion of
people coming from other OSes:
https://superuser.com/questions/691364/exponent-replacement-2-%C2%B2

There is setxkbmap fr -variant nodeadkeys but it disables all of them
including ê ö ï etc


On Sat, Jul 25, 2026 at 2:06 AM Ben Haller via Interest
<interest at qt-project.org> wrote:
>
> Hi Thiago (and I think this will reply to Max as well),
>
> OK, so.  I'm only used to American keyboards on macOS, in which context
> (as far as I can tell) this concept of "dead keys" doesn't exist, so I'm
> unfamiliar with this territory.  What I'm familiar with is the other
> kind of method you describe, "pressing <Compose> <asciicircum> and a
> number", and I'm fine with that – then the intent of the user to produce
> these special characters is clear, and whatever happens next is their
> responsibility.  :->
>
> I ought to have mentioned that this came up in France.  I was teaching a
> workshop to 30 French students, and out of those thirty, maybe 4 or 5 of
> them had this same problem.  They didn't understand what was happening,
> and they came to me asking for help -- "how do I type x^2, it keeps
> giving me a superscripted 2!" -- and I was mystified.  None of them had
> any idea why it was happening, and none of them had chosen this keyboard
> functionality intentionally. Eventually, by trial and error, we
> discovered together that (in your notation) <dead_circumflex> followed
> by a space, or I think also pressing <dead_circumflex> again, would
> provide <asciicircum>.  They wanted to turn this keyboard layout feature
> off, so that they could type code normally, and I didn't know how they
> could do that (and I still don't).
>
> So, Thiago, you asked "Why do you want to interfere with other users'
> ability to type "O(n²)" in a comment?".  I have no desire to interfere
> with their ability to do that.  But the problem is that, unlike the
> "<Compose> <asciicircum>" method, the users here did not _intend_ to get
> a <dead_circumflex> instead of an <asciicircum>; it was happening to
> them against their will, and neither they nor I knew how to fix it (and
> even once we discovered a fix, it was annoying and inconvenient for them).
>
> So OK, user error; they don't know their own keyboard layout, they don't
> understand their own operating system, their fault.  But weighing
> between "interfere with other users' ability to type "O(n²)" in a
> comment" and "make it so clueless users can type "x^2" in their code
> without getting lost in a rabbit hole they don't understand", the latter
> seems clearly preferable; I would happily flip that switch if I could.
> The user who is well-informed enough to understand all this and actually
> want to type O(n²) in a comment will presumably know to do <Compose>
> <asciicircum> to get what they want.
>
> But I guess it sounds like there's nothing I can (reasonably) do about
> this anyway, so the discussion is somewhat moot.  :-<  I guess I just
> don't like the fundamental concept of "dead keys", because it seems like
> it just confuses novice users by doing magical things that they don't
> know how to turn off.  Oh well.
>
> Thanks for the replies; I understand the problem better now, and thus
> can explain it to my users better, even if I (and they) don't like it.
>
> Cheers,
> -B.
>
> Benjamin C. Haller
> Messer Lab
> Cornell University
>
>
> On 7/25/26 3:21 AM, Thiago Macieira wrote:
> > On Friday, 24 July 2026 12:45:07 Pacific Daylight Time Ben Haller via Interest
> > wrote:
> >> In the language being edited, ^ is the exponentiation operator, so the
> >> user wants to type "x^2" and have that mean "x squared" in the language
> >> on question.  An issue recently arose where some of my users on Linux
> >> would type the "^2" and it would be turned into a superscripted 2 (!).
> > Cannot reproduce in the widgetgallery example, Qt 6.13, Wayland and X11
> > (XWayland), using no special input method.
> >
> > Are you sure your users are using the asciicircum key, not a dead_circumflex?
> > Have them run xev and press the key. If it prints:
> >
> > KeyPress event, serial 39, synthetic NO, window 0x1200001,
> >      root 0x43a, subw 0x0, time 130046808, (2009,-1014), root:(3839,76),
> >      state 0x91, keycode 15 (keysym 0x5e, asciicircum), same_screen YES,
> >
> > Then we have to investigate. What input method are they using?
> >
> > If it prints
> >
> > KeyPress event, serial 39, synthetic NO, window 0x1200001,
> >      root 0x43a, subw 0x0, time 130081096, (2009,-1014), root:(3839,76),
> >      state 0x11, keycode 15 (keysym 0xfe52, dead_circumflex), same_screen YES,
> >
> > Then it's expected because it's a dead key. If you don't want it to affect the
> > next key, press space.. <dead_circumflex> followed by a number will produce
> > superscripts: ¹²³⁴⁵⁶⁷⁸⁹⁰. There are also ⁽ and ⁾. The same can be accomplished
> > by pressing <Compose> <asciicircum> and a number. Likewise,
> > <Compose>,<underscore> followed by a number will produce subscripts:
> > ₁₂₃₄₅₆₇₈₉₀₍₎.
> >
> >> My question: how can I customize my QPlainTextEdit subclass to prevent
> >> this?
> > It's not QPlainTextEdit's doing. This happens much deeper. If the user is
> > using an input method, then the translation happens there. You'll have to work
> > out with the input methods (all of them).
> >
> > If there is no input method, it might be inside Qt: deep inside the XCB plugin
> > (for X11) and Wayland plugin (for Wayland) that translate the sequence of keys
> > to a symbol. They are obeying the xkb keyboard and Composition rules. If you
> > REALLY want to do this, you'll need to patch the libraries and recompile.
> >
> >>   I'd also like to not interfere with typing of accented
> >> characters, emojis, etc.; I just want to prevent this specific feature
> >> from activating in my code view, because the '^' character is
> >> significant and I don't want it to be re-interpreted by the OS
> > Why do you want to interfere with other users' ability to type "O(n²)" in a
> > comment?
> >
> >
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