Golang Learning: Interface replication and interface query

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package main import  "FMT" Type ifile interface {read () Write ()}type IReader  interface {read ()}type file struct {}func  (f *file)  Read ()  {} func  (F *file)  write ()  {}func main ()  {f := new (File) var f1  ifile = f  // ok  because file implements all the methods in IFile VAR F2 IREADER = F1  // ok  because IFile contains all the methods in Ireader// var f3 ifile = f2     // error  because Ireader does not meet ifile (less one method)// var f3 ireader = new (File)//  ok  because file implements all the methods in Ireader// var f4 ifile = f3           // error  because Ireader does not meet ifile  ibid. How to solve it?   to query the//  interface query with an interface//  this if statement checks if the object instance that the File1 interface points to implements the IFile interface//  executes the specific code if//  is implemented.   NOTE: The emphasis here is on object instances, that is, the new (File)// file contains all the methods in IFile//  so ok = trueif f5, ok := f3. (IFile);  ok {fmt. Println (F5)}//  asks the interface whether the object it points to is a type//  The IF statement determines whether the object instance that the File1 interface points to is *file type//  still Okif f6, ok  := f3. (*file);  ok {fmt. Println (f6)}fmt. Println (F1, F2, F3)}