Possibly not easy to tell at that point if it is a file or network descriptor
and the worst case is an additional read that returns EOF on an empty file?
> On Jul 7, 2016, at 4:06 PM, Alexander Ilin <ajs...@yandex.ru> wrote:
>
> Hello, John!
>
> TCP/UDP streams are not seekable, so it should return f, and it does. Why
> does it not return 0 for seekable empty (file) streams?
>
> A bigger quote from the documentation:
>
> Word description
> Returns the length of the data supplied by stream, or f if the stream is not
> seekable or has unknown length.
>
> Notes
> Stream seeking is not supported on streams that do not have a known length,
> e.g. TCP/IP streams.
>
> 08.07.2016, 00:42, "John Benediktsson" <mrj...@gmail.com>:
>> For tcp/udp file descriptors, they can return 0 length sometimes and we want
>> to then return `f` so we read to EOF.
>>
>>> On Jul 7, 2016, at 2:26 PM, Alexander Ilin <ajs...@yandex.ru> wrote:
>>>
>>> Hello!
>>>
>>> OK, ignore that last message, I can see now that it works.
>>>
>>> Another question, though. This one is about io.ports:
>>>
>>> M: buffered-port stream-length
>>> handle>> handle-length [ f ] when-zero ;
>>>
>>> Why does it never return 0? For instance, what if I open an empty file for
>>> reading, I'd expect it to return 0, and "f" only for streams that are not
>>> seekable.
>>>
>>> { 0 }
>>> [
>>> "empty.txt" binary [ input-stream get stream-length ] with-file-reader
>>> ] unit-test
>>>
>>> From the documentation on stream-length:
>>> Word description
>>> Returns the length of the data supplied by stream, or f if the stream is
>>> not seekable or has unknown length.
>>>
>>> Why not return 0 so that I could test that with if-zero?
>
> ---=====---
> Александр
>
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