You are right. )SAVE is indeed a command, and the output is meant for
humans to read. It should be local time. That said, I don't mind seeing the
timezone there as well. It's helpful when looking at logs (I'm speaking
from experience here since I'm right now sitting in a hotel room in Sydney,
two timezones away from where I live).

Regards,
Elias


On 9 May 2014 20:17, Blake McBride <blake1...@gmail.com> wrote:

> Given that )SAVE is a command and not a function (something intended to be
> used by another program), I think it is clear that it should display local
> time without any timezone information.
>
> Secondly, the output message from )SAVE is for convenience of the
> immediate programmer doing the work, and not some data to be used to
> communicate across countries.  If I want to do that, Unix gives plenty of
> information associated with the saved file.
>
> So, in general, I agree with you say completely.  It just doesn't apply to
> the )SAVE commend (except in possible very rare cases.)
>
> In the case of ⎕TS, that too should return local time for many reasons.
>  Creating an additional ⎕ function to return GMT time is fine and useful
> too.
>
> Thanks.
>
> Blake
>
>
>
> On Fri, May 9, 2014 at 6:56 AM, Elias Mårtenson <loke...@gmail.com> wrote:
>
>> Before I continue further, I want to emphasise that there is a problem
>> with the output of )SAVE. It may, however, be different from your opinion.
>>
>> There are two different things to think about when working with time:
>>
>>    - Displaying time information for the user's benefit
>>    - For processing by a computer program
>>
>> In the first case, it's natural to display local time. Usually one
>> displays the local time followed by the an indication of what timezone was
>> used when displaying this value. This is where GNU APL does things wrong,
>> as it's displaying GMT along with the timezone information where the save
>> happened. This is not right. When displaying GMT time, one should indicate
>> the timezone as Z, UTC, GMT+0, or something similar.
>>
>> The second case is when the number is returned for the purpose of further
>> computation. This number should (almost) always be UTC. There are of course
>> many reasons for this, but the most compelling one is that it's very easy
>> to convert a UTC timestamp into any other timezone for display to a user,
>> but converting *back* from local time can in some cases actually be
>> completely impossible (think daylight savings, and other adjustments).
>>
>> As for time manipulation, it's an incredibly complicated subject
>> (something I have worked a lot on in my career) and I would certainly like
>> to see something simple, such as the Unix time_t used for time
>> representation. The worst one I've come across is the ⎕TS form, which is
>> pretty much impossible to work with except for displaying the current time
>> to the user.
>>
>> There are other arguments that can be made, but my mail is long enough
>> already and I think my position has been made. :-)
>>
>> Regards,
>> Elias
>>
>>
>> On 9 May 2014 19:42, Blake McBride <blake1...@gmail.com> wrote:
>>
>>> Greetings,
>>>
>>> Two additional problems with the )SAVE message:
>>>
>>> 1.  Drop the timezone info i.e. "(GMT -5)"
>>>
>>> 2.  Display local time instead of GMT time.
>>>
>>> My entire life revolves around my local time.  GMT time is largely
>>> meaningless to me.  For me, GMT time only has value when I am trying to
>>> coordinate something with someone in another part of the world.  I can do
>>> the translation, when necessary, at that time.  As it is, I have to do time
>>> math each time I want to use the value/message )SAVE returns.
>>>
>>> Thanks.
>>>
>>> Blake
>>>
>>>
>>> On Thu, May 8, 2014 at 11:05 PM, Blake McBride <blake1...@gmail.com>wrote:
>>>
>>>> Greetings,
>>>>
>>>> I believe the )SAVE command should display the name of the workspace
>>>> after the date and time.  I am looking at the Gilman and Rose APL2 book and
>>>> that's the way they show it.  (In addition to my memory.)
>>>>
>>>> Thanks.
>>>>
>>>> Blake
>>>>
>>>>
>>>
>>
>

Reply via email to