Date classes

J J azreal1977 at hotmail.com
Fri Apr 20 06:50:45 UTC 2007


Oh, and thanks for the information.


>From: "Hernan Wilkinson" <hernan.wilkinson at gmail.com>
>Reply-To: The general-purpose Squeak developers 
>list<squeak-dev at lists.squeakfoundation.org>
>To: "The general-purpose Squeak developers 
>list"<squeak-dev at lists.squeakfoundation.org>
>Subject: Re: Date classes
>Date: Tue, 17 Apr 2007 10:10:49 -0300
>
>Just to give you a fast review of what I remember (I developed the model
>that Maxi Taborda converted into Chalten):
>1) Chronos supports many calendars, Chalten only the Gregorian Calendar
>2) Chronos supports time zones, Chalten does not
>3) Choros is huge (as you mentions), Chalten is more manageable (because it
>just model the Gregorian Calendar)
>4) Chronos lacks some abstractions that Chalten has, like Day of Month and
>others (I don't remember now...there are a couple of mails that I and the
>guy that created Chronos wrote about these issues, like one year ago)
>5) Chalten is based on a arithmetic model that allows you to represent time
>measurements easily (like 3 days, 5 months, etc). These objects are
>polymorphic with numbers respect to the arithmetic messages such as +, -, 
>*,
>etc., that means that you can use them in arithmetic formulas
>5) And of course, I like Chalten's model more that Chronos :-). For me it 
>is
>easier to use, but this is just a matter of taste...
>
>There is a paper we wrote 2 years ago about the problems that the Smalltalk
>date classes have and the advantages of having a better model. If you are
>interested on having better date and time classes, I recommend you to read
>the paper... you may not like it, but at least you will see other people
>ideas...
>We use that model (Chalten) in a production system and we believe it 
>allowed
>us to avoid many common mistakes related to financial systems.... but hey,
>that's just a feeling, nothing I can prove formally.
>
>I hope you can do something useful.
>Bye,
>Hernan.
>
>
>On 4/16/07, J J <azreal1977 at hotmail.com> wrote:
>>
>>I have looked at Cronos but it is really huge, and the classes that come
>>with the image are already very close.  I will have to look at Chalten,
>>but
>>what is wrong with a few upgrades to the classes that come with Squeak?
>>
>> >From: "Hernan Wilkinson" <hernan.wilkinson at gmail.com>
>> >Reply-To: The general-purpose Squeak developers
>> >list<squeak-dev at lists.squeakfoundation.org>
>> >To: "The general-purpose Squeak developers
>> >list"<squeak-dev at lists.squeakfoundation.org>
>> >Subject: Re: Date classes
>> >Date: Mon, 16 Apr 2007 14:28:09 -0300
>> >
>> >Before doing something with Date, I recommend you to take a look at
>> >"Chalten" or "Cronos". Chalten is in SqueakSource.... I think Cronos 
>>too.
>> >
>> >Hernan.
>> >
>> >On 4/16/07, J J <azreal1977 at hotmail.com> wrote:
>> >>
>> >>Hi all,
>> >>
>> >>I am doing some stuff with dates and I noticed the date classes that
>>come
>> >>with the default Squeak image are very nice and very close to having
>> >>everything I would want.  But there are a few inconsistencies here and
>> >>there, and things missing that would make things easier.
>> >>
>> >>So what is the procedure to updating this?  I think it's part of the
>>core
>> >>system so I probably can't just do a monicello package update
>> >>somewhere?  Do
>> >>I have to do it through mantis?
>> >>
>> >>Thanks,
>> >>Jason
>> >>
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>>
>> >
>>
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>>


>

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