running go1.1beta2.linux-amd64
Just a few issues regarding bufio Scanner and zero length reads of the underlying io.Reader.
1. It is not documented that the scanner also stops on a zero length read.
2. If the underlying reader returns a zero length read with an error that is
not io.EOF the error is masked and Err() returns nil.
Eg, this program will not print out the error.
package main
import (
"bufio"
"errors"
"fmt"
)
type errReader struct{}
func (t *errReader) Read(p []byte) (int, error) {
return 0, errors.New("Random Err")
}
func main() {
scanner := bufio.NewScanner(new(errReader))
for scanner.Scan() {
fmt.Println(scanner.Text())
}
if err := scanner.Err(); err != nil {
fmt.Println(err)
}
}
3. I don't see in any of the other standard library readers documentation
that they guarantee no zero length reads. If I am being paranoid, can
I safely use them without the scan prematurely terminating before EOF?
