This must be a bug. A stream backed by a file is seekable so 0 should
be returned as its length.
2016-07-08 1:32 GMT+02:00 John Benediktsson <mrj...@gmail.com>:
> 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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