Is there a way to clear an OutBuffer, but without freeing the internally managed buffer? Something similar to std.array.appender.clear method. Intent would be to reuse the OutBuffer, but without reallocating memory for the buffer.

--Jon

On 05/22/2016 11:59 AM, Jon Degenhardt wrote:
> Is there a way to clear an OutBuffer, but without freeing the internally
> managed buffer? Something similar to std.array.appender.clear method.
> Intent would be to reuse the OutBuffer, but without reallocating memory
> for the buffer.
>
> --Jon

Currently not possible. Enhancement request perhaps?

Looking at the implementation, setting its 'offset' member seems to work. Based on example from documentation:

import std.outbuffer;

void main() {
    OutBuffer b = new OutBuffer();
    b.writefln("a%sb", 16);
    assert(b.toString() == "a16b\n");

    b.offset = 0;
    b.writefln("a%sb", 16);
    assert(b.toString() == "a16b\n");
}

Bug report perhaps? :)

Ali

On Sunday, 22 May 2016 at 23:01:07 UTC, Ali Çehreli wrote:
> On 05/22/2016 11:59 AM, Jon Degenhardt wrote:
>> Is there a way to clear an OutBuffer, but without freeing the internally
>> managed buffer? Something similar to std.array.appender.clear method.
>> Intent would be to reuse the OutBuffer, but without reallocating memory
>> for the buffer.
>>
>> --Jon
>
> Currently not possible. Enhancement request perhaps?
>
> Looking at the implementation, setting its 'offset' member seems to work. Based on example from documentation:
>
> import std.outbuffer;
>
> void main() {
>     OutBuffer b = new OutBuffer();
>     b.writefln("a%sb", 16);
>     assert(b.toString() == "a16b\n");
>
>     b.offset = 0;
>     b.writefln("a%sb", 16);
>     assert(b.toString() == "a16b\n");
> }
>
> Bug report perhaps? :)
>
> Ali

Thanks. Enhancement request: https://issues.dlang.org/show_bug.cgi?id=16062

On Monday, 23 May 2016 at 03:03:12 UTC, Jon Degenhardt wrote:
> On Sunday, 22 May 2016 at 23:01:07 UTC, Ali Çehreli wrote:
>> On 05/22/2016 11:59 AM, Jon Degenhardt wrote:
>>> [...]
>>
>> Currently not possible. Enhancement request perhaps?
>>
>> Looking at the implementation, setting its 'offset' member seems to work. Based on example from documentation:
>>
>> import std.outbuffer;
>>
>> void main() {
>>     OutBuffer b = new OutBuffer();
>>     b.writefln("a%sb", 16);
>>     assert(b.toString() == "a16b\n");
>>
>>     b.offset = 0;
>>     b.writefln("a%sb", 16);
>>     assert(b.toString() == "a16b\n");
>> }
>>
>> Bug report perhaps? :)
>>
>> Ali
>
> Thanks. Enhancement request: https://issues.dlang.org/show_bug.cgi?id=16062


It was once proposed to have start & stop, which could also imply that it's resettable:

https://github.com/dlang/phobos/pull/3362

On Monday, 23 May 2016 at 03:03:12 UTC, Jon Degenhardt wrote:
>> Currently not possible. Enhancement request perhaps?
>>
>> Looking at the implementation, setting its 'offset' member seems to work. Based on example from documentation:
>>
>> import std.outbuffer;
>>
>> void main() {
>>     OutBuffer b = new OutBuffer();
>>     b.writefln("a%sb", 16);
>>     assert(b.toString() == "a16b\n");
>>
>>     b.offset = 0;
>>     b.writefln("a%sb", 16);
>>     assert(b.toString() == "a16b\n");
>> }
>>
>> Bug report perhaps? :)
>>
>> Ali
>
> Thanks. Enhancement request: https://issues.dlang.org/show_bug.cgi?id=16062

Is there a consensus on this? Does this really need a clear method seeing as though you can reset the offset directly?

On Wednesday, 25 May 2016 at 19:42:43 UTC, Gary Willoughby wrote:
> On Monday, 23 May 2016 at 03:03:12 UTC, Jon Degenhardt wrote:
>>> Currently not possible. Enhancement request perhaps?
>>>
>>> Looking at the implementation, setting its 'offset' member seems to work. Based on example from documentation:
>>>
>>> import std.outbuffer;
>>>
>>> void main() {
>>>     OutBuffer b = new OutBuffer();
>>>     b.writefln("a%sb", 16);
>>>     assert(b.toString() == "a16b\n");
>>>
>>>     b.offset = 0;
>>>     b.writefln("a%sb", 16);
>>>     assert(b.toString() == "a16b\n");
>>> }
>>>
>>> Bug report perhaps? :)
>>>
>>> Ali
>>
>> Thanks. Enhancement request: https://issues.dlang.org/show_bug.cgi?id=16062
>
> Is there a consensus on this? Does this really need a clear method seeing as though you can reset the offset directly?

As an end-user, I'd have more confidence using a documented mechanism. If it's setting a public member variable, fine, if it's a method, also fine.

The 'offset' member is not part of the publicly documented API.  Looking at the implementation, it doesn't appear 'offset' is intended to be part of the API. Personally, I'd add a method to keep 'offset' out of the public API. However, simply documenting it is an option as well.