func (b *bufioR) fill() error {
	b.compact()

	if b.w < len(b.buf) {
		n, err := b.rd.Read(b.buf[b.w:])
		b.w += n
		return err
	}
	return nil
}
// fill tries to read more data into the buffer
fill tries to read more data into the buffer
// fill tries to read more data into the buffer
func (b *bufioR) fill() error {
	b.compact()
	if b.w < len(b.buf) {
		n, err := b.rd.Read(b.buf[b.w:])
		b.w += n
		return err
	}
	return nil
}
func ( b * bufioR ) fill ( ) error { b . compact ( ) if b . w < len ( b . buf ) { n , err := b . rd . Read ( b . buf [ b . w : ] ) b . w += n return err } return nil }
fill tries to read more data into the buffer
fill tries to read more data into the buffer