[Pharo-dev] In-memory FileSystem write streams not being polymorphic

Chris Muller asqueaker at gmail.com
Wed Nov 13 11:48:07 EST 2013


I know nothing about Xtreams but, IMO, this obsession with sterility
borders on mental illness.

"All sort of un-needed complexity?"  That's overstating it a bit,
don't you think?

So you must really feel stressed that ALL Object's, in fact, have a
#name, huh?  I admit this seems to push the limits but...

what's the point of having any kind of different streams at all then?
It's the _differences_ between them that makes composing them useful.
Compression, encryption, filtering, sockets, files, circular, etc.
You think you'll be able to do all that and get away with all of them
having exactly the same API?

IMHO working around that, passing extra objects around, sounds more
stressful than letting a stream on a _file_ know its filename..

> If it really need it, the application certainly can retrieve the name from a higher level object (a FIleReference, FileDirectory or whatever).

How does that solution allow uniformity in stream-using code?

On Wed, Nov 13, 2013 at 9:58 AM, Nicolas Cellier
<nicolas.cellier.aka.nice at gmail.com> wrote:
> Yes, a Wrapper would provide the legacy API.
>
> And yes, the name of a stream should better not be part of the API.
> Most stream don't have a name, and adding such API adds all sort of
> un-needed complexity.
> It's an internal detail that can eventually help for reporting error if
> accessible, but nothing more.
>
> If it really need it, the application certainly can retrieve the name from a
> higher level object (a FIleReference, FileDirectory or whatever).
>
>
> 2013/11/13 Chris Muller <asqueaker at gmail.com>
>>
>> On Tue, Nov 12, 2013 at 7:31 AM, Nicolas Cellier
>> <nicolas.cellier.aka.nice at gmail.com> wrote:
>> > It's just a matter of selecting a strategy. I've proposed two:
>> > A) create a wrapper class for legacy Stream compatibility selectors
>> > B) create extensions for Legacy Stream compatibility selectors
>> > My preference goes to A)
>>
>> By wrappers you mean the Xtreams are the innards doing the work and
>> the wrappers providing the legacy API?
>>
>> This would be a great way to test Xtreams.
>>
>> > The legacy support MUST be minimal (next nextPut: nextPutAll: peek upTo:
>> > ...), otherwise we will import all the cruft in Xtream and would go back
>> > to
>> > our starting point...
>> > Once the minimal support written (a few hours should be enough), we
>> > should
>> > gradually switch each every legacy Stream usage -> Xtream.
>> >
>> > An area which require more work is those Streams that have mixed
>> > conventions
>> > (one portion is interpreted as text, another as binary).
>> > In theory that's easy, we just have two streams and they both wrap on a
>> > low
>> > level binary stream, but that means we have to be very cautious with
>> > buffers
>> > and caches.
>> >
>> > Another area of work is usage of ugly selectors like name (we try to
>> > access
>> > the file name from the Stream API, arghh). Those usages are bad and
>> > require
>> > a rewrite.
>>
>> Are you saying a FileStream knowing its #name or #filename is bad?
>>
>




More information about the Pharo-dev mailing list