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digitalmars.D.learn - DateTime formatting

reply bauss <jj_1337 live.dk> writes:
I can't seem to find anything in Phobos that allows you to 
specify custom formats for dates.

Am I on my own or is there already such functionality?

I'm interested in a formatter with the possibility to output ex.:

December 20th, 2017 10:00 AM

All I could find was toSimpleString(), but it seem to use a 
pre-defined format like:
YYYY-Mon-DD HH:MM:SS
Dec 20 2017
next sibling parent Steven Schveighoffer <schveiguy yahoo.com> writes:
On 12/20/17 9:30 AM, bauss wrote:

 I can't seem to find anything in Phobos that allows you to specify 
 custom formats for dates.
 
 Am I on my own or is there already such functionality?


You are on your own. Some of the pieces are available, but having 
support for everything you may want to do with calendars and 
representation is quite a lot to add to Phobos.


 I'm interested in a formatter with the possibility to output ex.:
 
 December 20th, 2017 10:00 AM


You will need to build yourself. I checked code.dlang.org, there doesn't 
seem to be anything (surprising).

-Steve
Dec 20 2017
prev sibling next sibling parent reply Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Wednesday, December 20, 2017 14:30:55 bauss via Digitalmars-d-learn 
wrote:

 I can't seem to find anything in Phobos that allows you to
 specify custom formats for dates.

 Am I on my own or is there already such functionality?

 I'm interested in a formatter with the possibility to output ex.:

 December 20th, 2017 10:00 AM

 All I could find was toSimpleString(), but it seem to use a
 pre-defined format like:
 YYYY-Mon-DD HH:MM:SS


At present, the only formats that Phobos supports are ISO, ISO Extended, and
Boost's simple time format. It does not yet have support for custom
date/time formatting beyond constructing the string yourself from the
properties on a DateTime or SysTime.

This was posted about recently in the Announce group though:

http://code.dlang.org/packages/datefmt

It might do what you want.

- Jonathan M Davis
Dec 20 2017
next sibling parent reply Steven Schveighoffer <schveiguy yahoo.com> writes:
On 12/20/17 1:50 PM, Jonathan M Davis wrote:

 This was posted about recently in the Announce group though:
 
 http://code.dlang.org/packages/datefmt


Hm... a search for "date" on code.dlang.org does not show this. Why not?

http://code.dlang.org/search?q=date

-Steve
Dec 20 2017
parent Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Wednesday, December 20, 2017 14:14:32 Steven Schveighoffer via 
Digitalmars-d-learn wrote:

 On 12/20/17 1:50 PM, Jonathan M Davis wrote:

 This was posted about recently in the Announce group though:

 http://code.dlang.org/packages/datefmt


 Hm... a search for "date" on code.dlang.org does not show this. Why not?

 http://code.dlang.org/search?q=date


Yeah, I don't know. Very weird. I only knew about it, because I remembered
the recent D.Announce post on it and could look up the name there.

- Jonathan M Davis
Dec 20 2017
prev sibling parent reply bauss <jj_1337 live.dk> writes:
On Wednesday, 20 December 2017 at 18:50:37 UTC, Jonathan M Davis 
wrote:

 On Wednesday, December 20, 2017 14:30:55 bauss via 
 Digitalmars-d-learn wrote:

 I can't seem to find anything in Phobos that allows you to 
 specify custom formats for dates.

 Am I on my own or is there already such functionality?

 I'm interested in a formatter with the possibility to output 
 ex.:

 December 20th, 2017 10:00 AM

 All I could find was toSimpleString(), but it seem to use a
 pre-defined format like:
 YYYY-Mon-DD HH:MM:SS


 At present, the only formats that Phobos supports are ISO, ISO 
 Extended, and Boost's simple time format. It does not yet have 
 support for custom date/time formatting beyond constructing the 
 string yourself from the properties on a DateTime or SysTime.

 This was posted about recently in the Announce group though:

 http://code.dlang.org/packages/datefmt

 It might do what you want.

 - Jonathan M Davis


Unfortunately I can't rely on any third-party packages for it :p

But thanks anyway   both of you.

I'll write my own function to do it :)
Dec 20 2017
parent reply Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Wednesday, December 20, 2017 21:36:00 bauss via Digitalmars-d-learn 
wrote:

 On Wednesday, 20 December 2017 at 18:50:37 UTC, Jonathan M Davis

 wrote:

 On Wednesday, December 20, 2017 14:30:55 bauss via

 Digitalmars-d-learn wrote:

 I can't seem to find anything in Phobos that allows you to
 specify custom formats for dates.

 Am I on my own or is there already such functionality?

 I'm interested in a formatter with the possibility to output
 ex.:

 December 20th, 2017 10:00 AM

 All I could find was toSimpleString(), but it seem to use a
 pre-defined format like:
 YYYY-Mon-DD HH:MM:SS


 At present, the only formats that Phobos supports are ISO, ISO
 Extended, and Boost's simple time format. It does not yet have
 support for custom date/time formatting beyond constructing the
 string yourself from the properties on a DateTime or SysTime.

 This was posted about recently in the Announce group though:

 http://code.dlang.org/packages/datefmt

 It might do what you want.

 - Jonathan M Davis


 Unfortunately I can't rely on any third-party packages for it :p

 But thanks anyway   both of you.

 I'll write my own function to do it :)


Well, if you can't use a 3rd party package, I suspect that you'd have to
write your own solution even if Phobos does finally get custom date/time
formatting, because what you're trying to do includes "th", which is
English-specific, and I'm not about to add localization/i18n stuff to
std.datetime. One of the reasons that I regret porting Boost's simple time
format over to std.datetime is that it includes English in it, which has
occasionally resulted in localization requests, and i18n is really way too
involved to put into Phobos.

I expect that I'll get around to finishing custom date/time formatting for
Phobos at some point, but it's not a high priority for me, and I have yet to
come up with a scheme for defining the formatting that doesn't seem terrible
to me.

- Jonathan M Davis
Dec 20 2017
parent bauss <jj_1337 live.dk> writes:
On Wednesday, 20 December 2017 at 22:38:06 UTC, Jonathan M Davis 
wrote:

 On Wednesday, December 20, 2017 21:36:00 bauss via 
 Digitalmars-d-learn wrote:

 On Wednesday, 20 December 2017 at 18:50:37 UTC, Jonathan M 
 Davis

 wrote:

 On Wednesday, December 20, 2017 14:30:55 bauss via

 Digitalmars-d-learn wrote:

 I can't seem to find anything in Phobos that allows you to 
 specify custom formats for dates.

 Am I on my own or is there already such functionality?

 I'm interested in a formatter with the possibility to 
 output ex.:

 December 20th, 2017 10:00 AM

 All I could find was toSimpleString(), but it seem to use a
 pre-defined format like:
 YYYY-Mon-DD HH:MM:SS


 At present, the only formats that Phobos supports are ISO, 
 ISO Extended, and Boost's simple time format. It does not 
 yet have support for custom date/time formatting beyond 
 constructing the string yourself from the properties on a 
 DateTime or SysTime.

 This was posted about recently in the Announce group though:

 http://code.dlang.org/packages/datefmt

 It might do what you want.

 - Jonathan M Davis


 Unfortunately I can't rely on any third-party packages for it 
 :p

 But thanks anyway   both of you.

 I'll write my own function to do it :)


 Well, if you can't use a 3rd party package, I suspect that 
 you'd have to write your own solution even if Phobos does 
 finally get custom date/time formatting, because what you're 
 trying to do includes "th", which is English-specific, and I'm 
 not about to add localization/i18n stuff to std.datetime. One 
 of the reasons that I regret porting Boost's simple time format 
 over to std.datetime is that it includes English in it, which 
 has occasionally resulted in localization requests, and i18n is 
 really way too involved to put into Phobos.

 I expect that I'll get around to finishing custom date/time 
 formatting for Phobos at some point, but it's not a high 
 priority for me, and I have yet to come up with a scheme for 
 defining the formatting that doesn't seem terrible to me.

 - Jonathan M Davis


Well a way to achieve it without putting i18n into Phobos would 
be something like being able to specify formatters.

Ex. you could have something like a global formatter, which is 
used if you don't pass a formatter to toString().

Example:
globalTimeFormatter = (fmt, time) {
    // fmt would be the string format passed to ex. 
DateTime.toString()
    // time would be the DateTime

    // return a formatted string based on what you give
};

If you give no formatter to DateTime.toString() like:
auto formattedTime = dateTime.toString("HH:mm:ss");

Then it will automatically use the "globalTimeFormatter".

However you should be able to also "override" the globalFormatter 
when needed like:
auto formattedTime = dateTime.toString("HH:mm:ss", (fmt, time) {
    // Same concept as the global formatter ...
});

Perhaps it could be a static member of DateTime, to avoid 
confusion on which time implementations it's used for. Eg. I'd 
argue that it shouldn't be usable for SysTime.

DateTime.globalFormatter = ...;

This would leave i18n etc. up to the caller.

This can basically be done ouselves using UFC, but something 
official in Phobos would be  great addition to be honest.

It would be a relative small implementation, but very useful.
Dec 20 2017
prev sibling parent codephantom <me noyb.com> writes:
On Wednesday, 20 December 2017 at 14:30:55 UTC, bauss wrote:

 I can't seem to find anything in Phobos that allows you to 
 specify custom formats for dates.


sometimes it's just better to take control of things yourself ;-)

https://forum.dlang.org/post/dmxdtciktpggcxybdlcn forum.dlang.org
Dec 20 2017