proposal: os/v2: File should be an interface

[robpike]

By analogy with #13473, os.File should also be an interface. That would permit a program to use files in the abstract sense, including implementations not provided by the os package.

[bradfitz]

Related: #5636 (VFS layer), in which we were never able to find a design that fit everybody's needs.

[mattn]

https://godoc.org/golang.org/x/net/webdav#FileSystem

This may be one of implementations.

[rsc]

I think I'd argue that io.File should be the interface but it's all moot now.

[bronze1man]

rsc How about follow interface?
I think following interface should work in go1.x

type FileV2 interface{
   io.ReadWriteCloser
   //....
}
func NewFileFromV2(v2 FileV2) *File{
  //...
}

[minux]

No. Please see my reply to a similar suggestion in #13473. Having version numbers in APIs is really ugly.

[rsc]

This is a long-term issue that we are not actively working on.