Such as? Do you mean the Go standard libraries for Go code?

Yacc clones exit for almost every language out there, and there are better ways to do parsing than yacc with its stone age error reporting.

I'd be really delighted if you could show me a better tool for writing a parser, given a grammar in Golang than goyacc. You're absolutely right that the error reporting in yacc isn't that modern, but it's very functional, very powerful and (best of all), a lot of people have experience with it.

I certainly couldn't find any better tools in Golang when I started, but I wouldn't be surprised if someone had started one since.

Tools like ANTLR, for example.

Parser generators based in attribute grammars is another example.

The language is called Go.