proposal: More Type-Safe File Handling

[gopherbot]

by vomjom:

I propose that Go implements a Reader interface for files that are read-
only and a Writer interface for files that are write-only.

The motivation is this type of program:

package main

import "os"

func main() {
    f, _ := os.Open("test.out", os.O_CREATE | os.O_RDONLY, 0644);
    defer f.Close();

    f.WriteString("foobar");
}


It succeeds in running, but doesn't output anything.  This kind of error 
can be caught safely at compile-time if WriteString() only belonged to a 
Writer interface.

Specifically, here's my proposal:

1. Get rid of os.O_RDONLY and os.O_WRONLY.

2. Keep os.Open.  os.Open would mean that you are opening a file for both 
reading and writing.

3. Make an os.OpenRead() and os.OpenWrite().  These would return read only 
and write only interfaces to files.

These Reader and Writer interfaces should be generic enough that they can 
be used in other settings (sockets and pipes, for example).

[gopherbot]

Comment 1 by vomjom:

Hmm, it looks like the necessary interfaces already exist in the "io" package.  Also, 
my desired behavior can be emulated simply by typing declaring "f" as "var f 
io.ReadCloser" in my example and using the appropriate functions from "io".
So, this proposal isn't really necessary.  Please close it.  Sorry for any 
inconvenience.

[gopherbot]

Comment 2 by vomjom:

By the way, I think it would be useful if users could close issues that they reported.

[agl]

Comment 3:

Status changed to Invalid.