Can I use a non-monospaced font in either Vim or gVim?

> not all code has matrices in it

It's not just matrices.

An array of colors in hexadecimal is a good example of something that will make your eyeballs bleed with a non-monospaced font.

I also tend to do matrix-style aligment with complex expressions that have repetitive patterns.

Composable, yes, as in compose movements with commands.

The thing is, that only works if the user is able to understand what a movement does and know exactly where the cursor ends up after a command.

With non-monospace fonts that is not possible, as users have no clear idea where the cursor will end up after, say, pressing j or k.

That's the point.

Many programmers believe that it is impossible, or at least impractical, to code effectively in a monospaced font.

For most kinds of code, this is a mistaken belief.

You only need a monospaced font if you want to use column alignment. But it's really quite rare that column alignment is necessary. It can almost always be replaced with simple indentation.

Here's what I mean by column alignment:

  function foo(firstArgument,
               secondArgumentFunctionCall(itsArgument,
                                          itsOtherArgument),
               thirdArgument) {
      bar();
  }

Obviously, those arguments won't line up in a proportional font. But this kind of column alignment is a bad practice anyway. It leads to excessive line lengths, spurious VCS diffs, and is just generally fiddly.

The Rust/Servo coding guidelines formerly mandated column alignment like this. But after seeing the problems it caused in their codebase, they switched to a pure indentation style like the one I've used for many years.

The idea is simple. Stop making a distinction between statements and expressions, and instead format expressions just as you would format blocks of statements:

  function foo(
      firstArgument,
      secondArgumentFunctionCall(
          itsArgument,
          itsOtherArgument
      ),
      thirdArgument
  ) {
      bar();
  }

Once you start using this kind of format, it no longer matters whether you use a monospaced or proportional font. It doesn't even matter whether you use tabs or spaces! The notion of "tabs for indentation, spaces for alignment" goes away when you don't use alignment.

I think every programmer should try using proportional fonts for a while. Even if you decide you prefer monospaced after all, it's an educational experience to see that monospaced fonts are just not necessary for most programming, and that tabs work fine once you stop using alignment.

> but basically you're saying all the monospaced fonts out there used by default in a ton of code editors are there for no reason.

That assertion only makes sense if you assume that indentation or even indentation style have no relevance in software development, and thus there is no reason to consider those basic requirements in any activity related to coding.