[noir_lord]

They probably should but code as text has a lot of draw backs (and some benefits of course) one of which is that the only way to document a lot of edge cases is via comments in the text which people don't like and in large/long lived codebases immediately start rotting.

I've seen far too much

    // Workaround for <Foo bug> in <Browser no one has used for a decade and we haven't supported for five years>

I've often thought that code should have 'layers' that can be toggled on/off (comments and comments by category been one case), often when I'm writing code I don't want to see the comments while I'm writing it since I go back through afterwards and add them and they otherwise just get in the way, it would be nice if I could toggle them on/of rather than just folding them.

I've actually given some thought to how you'd implement it but I really need to hack up a proof of concept to see whether it's something I actually find useful (pass the sniff test).

[mike-cardwell]

With a js app packaged using babel, you can use the https://babeljs.io/docs/en/next/babel-preset-env.html preset to specify which browsers you want to support, and it will only transpile the features necessary to support those browsers. You can for example tell it you only want to support browsers with >0.25% of the browser market share, and it will figure out which browsers that includes and which features those browsers have.