stream-external-format only accepts file-streams
In CLHS stream-element-type, the single argument stream
is specified to be a file-stream
. I think this means two-way-stream
, concatenated-stream
, and string-stream
are not allowed for stream-external-format
.
See also #37 (closed). This is complicated; the spec is a bit messy on this because broadcast-stream explicitly says stream-external-format
works, even though it is not a file-stream
.