子包装中的可见性

Question

How's the visibility of members from a sub-package to its root package?

This is what I mean:

foo          // the "root" package
foo/utils    // a sub-package
foo/tools    // another sub-package

Can foo access private members of foo/utils and foo/tools or do they act as separate, independant packages?

Answer 1

Go has no concept of sub-directories nor sub-packages. Packages are separate from each other. The import path "foo/utils" is just an import path (a method of how to find the package) - the string "foo/utils" has no significance other than locating the package on local disk or in the Internet.

foo cannot access private members of foo/utils.

In Go1, each directory in a source tree corresponds to a single package. More about this can be found here: the go command.