<div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>Additionally Chronos also supports nominal time and leap seconds.</blockquote><div><br>
Maxi Taborda is enhancing Chalten adding that functionality... but is going to take some time :-) ... <br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> 5) Chalten is based on a arithmetic model that allows you to represent time<br>> measurements easily (like 3 days, 5 months, etc).<br><br>That won't work in Squeak because these methods are already by the<br>Squeak Chronology (unless you have classboxes). It might work in VW
<br>though.</blockquote><div><br>It works on Squeak, VW, VisualAge, Dolphin and GemStone that are the Smalltalk were Chalten has been migrated to. Look at Aconcagua, the model that takes care of this.<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> These objects are<br>> polymorphic with numbers respect to the arithmetic messages such as +, -, *,<br>> etc., that means that you can use them in arithmetic formulas<br><br>That's true to a certain extent in Chronos for example you can:
<br>Timepoint now - (CalendarDuration months: 1)<br>(CalendarDuration months: 1) * 5<br>but you can't:<br>5 * (CalendarDuration months: 1)</blockquote><div><br>Ok, but it is not only the functionality what it is important for us... for us it is also important the way you "write" these things... for example, with Chalten/Aconcagua you can write:
<br><br>5 * month ---> Equivalent to 5 * (CalendarDuration months: 1)<br>5 * meter / (second * second) --> A measure of acceleration if you create meter as a unit using Aconcagua<br>1/10 * year --> Represents an interest rate of 10% yearly.
<br><br>As you can see, time measure are not only related only to the time domain but used in other domains... that is way for us it is important to support this type of behavior and in a DSL way...<br><br>Bye, <br>Hernan.
<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> 5) And of course, I like Chalten's model more that Chronos :-). For me it is
<br>> easier to use, but this is just a matter of taste...<br>><br>> There is a paper we wrote 2 years ago about the problems that the Smalltalk<br>> date classes have and the advantages of having a better model. If you are
<br>> interested on having better date and time classes, I recommend you to read<br>> the paper... you may not like it, but at least you will see other people<br>> ideas...<br>> We use that model (Chalten) in a production system and we believe it allowed
<br>> us to avoid many common mistakes related to financial systems.... but hey,<br>> that's just a feeling, nothing I can prove formally.<br>><br>> I hope you can do something useful.<br>> Bye,<br><br>
Chronos is a bit ugly in Squeak because Squeak does not support<br>namespaces which means that classes that model the same concept as<br>Squeak Chronology classes have different names (unless you mess with<br>shared pools). Also loading it is a bit of a pain with Monticello
<br>(this is the fault of Monticello and not Chronos).<br><br>Cheers<br>Philippe<br><br>> Hernan.<br>><br>><br>> On 4/16/07, J J <<a href="mailto:azreal1977@hotmail.com">azreal1977@hotmail.com</a>> wrote:
<br>> > I have looked at Cronos but it is really huge, and the classes that come<br>> > with the image are already very close. I will have to look at Chalten,<br>> but<br>> > what is wrong with a few upgrades to the classes that come with Squeak?
<br>> ><br>> > >From: "Hernan Wilkinson" <<a href="mailto:hernan.wilkinson@gmail.com">hernan.wilkinson@gmail.com</a>><br>> > >Reply-To: The general-purpose Squeak developers<br>> > >list<
<a href="mailto:squeak-dev@lists.squeakfoundation.org">squeak-dev@lists.squeakfoundation.org</a>><br>> > >To: "The general-purpose Squeak developers<br>> > >list"<<a href="mailto:squeak-dev@lists.squeakfoundation.org">
squeak-dev@lists.squeakfoundation.org</a>><br>> > >Subject: Re: Date classes<br>> > >Date: Mon, 16 Apr 2007 14:28:09 -0300<br>> > ><br>> > >Before doing something with Date, I recommend you to take a look at
<br>> > >"Chalten" or "Cronos". Chalten is in SqueakSource.... I think Cronos too.<br>> > ><br>> > >Hernan.<br>> > ><br>> > >On 4/16/07, J J <<a href="mailto:azreal1977@hotmail.com">
azreal1977@hotmail.com</a>> wrote:<br>> > >><br>> > >>Hi all,<br>> > >><br>> > >>I am doing some stuff with dates and I noticed the date classes that<br>> come<br>> > >>with the default Squeak image are very nice and very close to having
<br>> > >>everything I would want. But there are a few inconsistencies here and<br>> > >>there, and things missing that would make things easier.<br>> > >><br>> > >>So what is the procedure to updating this? I think it's part of the
<br>> core<br>> > >>system so I probably can't just do a monicello package update<br>> > >>somewhere? Do<br>> > >>I have to do it through mantis?<br>> > >><br>> > >>Thanks,
<br>> > >>Jason<br>> > >><br>> ><br>> >>_________________________________________________________________<br>> > >>Download Messenger. Join the i'm Initiative. Help make a difference
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><br>><br>><br><br></blockquote></div><br>