DateTime custom string format

[Robert Schadek via Digitalmars-d-learn]

On 06/03/2014 08:22 PM, Jonathan M Davis via Digitalmars-d-learn wrote:
> On Tue, 03 Jun 2014 19:39:14 +0200
> Robert Schadek via Digitalmars-d-learn
> <digitalmars-d-learn at puremagic.com> wrote:
>
>> On 06/03/2014 07:12 PM, Jonathan M Davis via Digitalmars-d-learn
>> wrote:
>>> On Tue, 03 Jun 2014 17:07:02 +0200
>>> Robert Schadek via Digitalmars-d-learn
>>> <digitalmars-d-learn at puremagic.com> wrote:
>>>
>>>> Is there a function in phobos that lets me do something like
>>>> DateTime.format("MM:DD:YYYY ....") with a DateTime instance?
>>> Not currently. It's on my todo list. I intend to get back to it
>>> after I've finished with splitting std.datetime (which I should get
>>> to fairly soon but have been doing some cleanup in std.datetime
>>> first), but I don't know when it will actually be ready. So, for
>>> now, you'd have to use std.string.format and the getters on
>>> DateTime.
>>>
>>> - Jonathan M Davis
>> Ok, I had people asking me for this because of my std.logger default
>> output format.
>>
>> Do you accept PRs for that?
> Well, I would prefer to do it myself, but I obviously can't say that I
> wouldn't accept it if someone else did it and did a good job of it. The main
> problem however is that we need to come up with a good formatting scheme -
> that is the format of the custom time strings. What C has doesn't cut it, and
> what I proposed a while back turned out to be too complicated.  There's this
> 3rd party library which had some interesting ideas:
>
> http://pr.stewartsplace.org.uk/d/sutil/doc/datetimeformat.html
>
> but I'm convinced that what's there is too simplistic. I'll need to dig up my
> old proposal and look at how I can simplify it (possibly making it more like
> what's at that link) without removing too much power from it.
>
> Once I have the custom time format strings sorted out, I intend to create both
> functions which take the format string as a runtime argument and those which
> take them as compile-time arguments and their corresponding "from" functions
> as well (e.g. toCustomString and fromCustomString). We'll end up with
> functions for SysTime, DateTime, Date, and TimeOfDay (possibly by templatizing
> functions or creating specifically named functions for each of them). My
> intention is to put them in std.datetime.format once std.datetime has been
> split (and they've been implemented) rather than sticking them on the types
> directly.
>
> I'll probably also look at adding a way to get at the exact pieces of
> information you want efficiently without having to have flags for everything
> in the custom time format strings, making it easier to create strings that are
> more exotic but still do so without having to call all of the individual
> getters (which isn't necessarily efficient). But by doing something like that
> I should be able to simplify the custom time format strings somewhat and avoid
> some of the more complicated constructs that I had in my previous proposal.
>
> - Jonathan M Davis
I see. I like that format functionality. Maybe I can find some time on
the weekend