BOM (Byte Order Mark) handling of the file. Initial @default.
If the file is opened for reading in text-mode and file<-bom
is not @off,
the file is checked for a UNICODE BOM signature. If found, file<-bom
is set to @on
and the source_sink<-encoding is set
accordingly.
If the file is opened for writing and file<-bom
= @on and the
encoding is a UNICODE encoding, a BOM marker is written to the file.
Note that this default behaviour returns consistent results on the
sequence below. If a BOM is detected on reading, one will be added on
writing the file and the encoding of the file will not be changed.
send(View, load, File),
...
send(View, save).
