I don't think thats really true about Haskell, unless you are talking about C code you've invoked through FFI in which case all bets are off in every language.

I don't think thats really true about Haskell, unless you are talking about C code you've invoked through FFI in which case all bets are off in every language. Isn't it a lot simpler to just say that Go has no feature support for immutable data? The fact that you can hide accessors in a package is small comfort if I have to read all the source code in that package to know the actual semantics.