binary - query whether a File was opened with a binary mode
file.binary()
Returns true if the new
File() call specified a mode that included 'b', and
false otherwise. Binary-mode files and text-mode
files allow different operations:
| I/O intrinsic | Text-mode | Binary-mode | 
|---|---|---|
| getchar | yes | yes | 
| putchar | yes | yes | 
| ungetc | yes | yes | 
| readstr | yes | yes | 
| read | yes (formatted) | yes (unformatted) | 
| yes | no | |
| say | yes | no | 
| write | no | yes | 
Bool indicating whether a File was opened with
a binary mode
TypeCheck if file is not a
File 
 AccessCheck if
file has been closed
        f = new File("foo.bin", "wb")
        f.binary()
    true