Adding/replacing/patching std libraries

I have a (self-written) runtime library which I have used in various programming projects over the years. It started life as a Pascal library in the early days of Turbo Pascal and has since progressed through incarnations in C, Perl and Lua. I am now contemplating to move this over to Go (not least because there are some interesting parallels between Go and Lua). A good part of Go's std library does more or less what my own libraries do (for instance, the flag package or the regex stuff) in which case I can either use them directly or get away with writing a small interface layer.

Problems start with those packages where my model is too different from Go's for a simple interface layer to hide the differences (a case in point are the directory-walking functions). I see two ways forward: re-implement my code as a Go package; or patch some of the existing Go runtime packages.

I am leaning towards the first option, not least because this will help me to get to grips with the language. Then again, I've often patched source code for my own requirements and I am comfortable with that approach. The changes would be localised and it shouldn't be too difficult to merge future version of Go's runtime library with my changes.

So is it feasible, advisable to do that or do I have to regard the Go sources as read only?

> So is it feasible ... ?

No. Everything will break once you touch the Go stdlib as every package out there relies on the stdlib.

> So is it ... advisable to do that ...?

No, not at all.

> [D]o I have to regard the Go sources as read only?

Yes.

Note that what you call "runtime" is not the Go runtime but the Go's standard library.