To me the main advantage would be that it makes regexes more readable, not more writable. Integrating melody in to a project seems like it would add more indirection which would make it more inconvenient to read. Feels like this would be more useful as a rust proc macro for example so that you can actually have it alongside your code in a convenient way rather than have it compile to ES6 regexes.

This is neat... will have to try it out next time I have a need.

I have to admit though, since ChatGPT came along... making regex has been infinity easier. Game changer.