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Question about writeStream

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JeremieRegnault

Question about writeStream

Hi,

I am writing tests with streams, and I noticed that a stream opened on a
string doesn't close, but FileStreams do close. Is it normal ?

--
Jérémie Regnault

Sven Van Caekenberghe-2

Re: Question about writeStream

> On 29 Jun 2017, at 16:07, Jérémie Regnault <[hidden email]> wrote:
>
> Hi,
>
> I am writing tests with streams, and I noticed that a stream opened on a
> string doesn't close, but FileStreams do close. Is it normal ?

How do you mean that ? That FileStreams close automatically ?

That is indeed the case, that they are closed as a finalization action (i.e. when they become garbage), but that I consider that a fail safe thing, not something you should rely on. They should be properly closed, like #readStreamDo: and #writeStreamDo: do.

Streams over collections such as Strings do not need closing, as there is no opening either. But general stream code better does.

> --
> Jérémie Regnault
>

Guillermo Polito

Re: Question about writeStream

In fact the question comes from the fact that they are not polymorphic and you should know if you're manipulating a closable stream or not...

Maybe a solution is indeed to use #writeStreamDo:, that should behave well even for in-memory, collection streams, no?

On Thu, Jun 29, 2017 at 4:58 PM, Sven Van Caekenberghe <[hidden email]> wrote:

> On 29 Jun 2017, at 16:07, Jérémie Regnault <[hidden email]> wrote:
>
> Hi,
>
> I am writing tests with streams, and I noticed that a stream opened on a
> string doesn't close, but FileStreams do close. Is it normal ?

How do you mean that ? That FileStreams close automatically ?

That is indeed the case, that they are closed as a finalization action (i.e. when they become garbage), but that I consider that a fail safe thing, not something you should rely on. They should be properly closed, like #readStreamDo: and #writeStreamDo: do.

Streams over collections such as Strings do not need closing, as there is no opening either. But general stream code better does.

> --
> Jérémie Regnault
>

Guille Polito

Research Engineer

French National Center for Scientific Research - http://www.cnrs.fr

Web: http://guillep.github.io

Phone: +33 06 52 70 66 13