Use Advanced Search to search the entire archive.
Re: AbstractQuantity's class
- From: Werner Keil <
>
- To:
- Subject: Re: AbstractQuantity's class
- Date: Tue, 16 Sep 2014 08:55:42 +0200
That's along the lines of similar ones in JDK or JavaMoney;-)
Would you avoid the of() method in concrete classes to solve Otavio's
Problem/question?
As Anatole is at Hackergarten, we can probably offer him to join if he
wants.
Cheers,
W
Am 16.09.2014 08:07 schrieb "Jean-Marie Dautelle"
<
>:
>
Hello,
>
Quantities would not extends any class, its purpose is to provide static
>
factory method. Starting with Java 8, interface may have static factory
>
(but Java 8 it is not your target).
>
I would stay away from static factory method, except to get the "quantity
>
factory" (cf. unit of measurement 6.x api):
>
MyQuantityFactory.getInstance().newQuantity("10 m");
>
Cheers,
>
JM
>
>
>
On Tue, Sep 16, 2014 at 12:37 AM, Werner Keil
>
<
>
>
wrote:
>
>
> Sorry but it is not the answer to the question you askd, there is no
>
> practice (see JSR 354) like MonetaryAmounts.of() or Collections.of().
>
>
>
> Those are merely facade methods, a Quantities extends AbstractQuantity
>
> makes no sense, it is just wrong.
>
> Seems we probably need Hackergarten or the community to ask them for the
>
> right name. It certainly is not Quantities based on all other APIs.
>
>
>
> Beside, if we start putting such facades like Quantities into the RI,
>
> where does that leave the SPI elements or how wold it use them?
>
>
>
>
>
>
>
> On Tue, Sep 16, 2014 at 12:28 AM, Werner Keil
>
> <
>
>
> wrote:
>
>
>
>> What exactly should "Quantities" be, a facade like "MonetaryAmounts",
>
>> etc. from JavaMoney??
>
>>
>
>> If it was to replace BaseQuantity, that is not a name for a concrete
>
>> class I'm afraid. The TemporalAmount used in JSR 310 is actually a
>
>> TemporalAmounts (since it represents more than a single amount) but if we
>
>> had
>
>> Quantities extends AbstractQuantity or
>
>> Quantities implements Quantity??
>
>>
>
>>
>
>> java.util.Collections does not implement java.util.Collection either, it
>
>> is merely a facade, no need for an of() there[?]
>
>> So what you suggested would be a facade along the lines of what Anatole
>
>> mentioned, but it cannot replace AbstractQuantity.
>
>>
>
>> Class.of() returns an instance of that class, so a Quantities facade
>
>> could offer a method like
>
>>
>
>> Quantities.getQuantityFactory(), but it can't extend or implement
>
>> Quantity, nor return a Quantity as such via of().
>
>>
>
>> Regards,
>
>> Werner
>
>>
>
>> On Mon, Sep 15, 2014 at 11:40 PM, Jean-Marie Dautelle <
>
>>
>
>
>> wrote:
>
>>
>
>>> Hi All,
>
>>> Indeed, JScience use Amount but with a different semantics (using that
>
>>> same name would create for me a headache due to name clashing).
>
>>> It should be noted that Amount has to be a class (not an interface) in
>
>>> order to provide static factory method (Java 7).
>
>>> Usually (at least in JScience), you will have something like Amount
>
>>> (interface) and Amounts with terminating s for the class holding static
>
>>> factory method to produce Amount instances.
>
>>> But since you intend to return Quantity types, I would suggest using
>
>>> Quantities.of(100d, SI.METRE) - That would be consistent with standard
>
>>> practices.
>
>>> Best regards,
>
>>> Jean-Marie.
>
>>>
>
>>>
>
>>> On Mon, Sep 15, 2014 at 9:51 PM, Werner Keil
>
>>> <
>
>
>>> wrote:
>
>>>
>
>>>> Dear Experts,
>
>>>>
>
>>>> If you don't see a conflict between a more general "Amount" class here
>
>>>> and other types in different value-oriented APIs like JSR 354, we may
>
>>>> take
>
>>>> the inspiration by the likes of JScience or ICU4J, both using *Amount
>
>>>> for
>
>>>> such types.
>
>>>>
>
>>>> ICU4J combines it with things like "Currency" in
>
>>>> http://icu-project.org/apiref/icu4j/com/ibm/icu/util/CurrencyAmount.html
>
>>>> the other concrete class is even called "TimeUnitAmount", but I would
>
>>>> not really see any of those as proper additions either.
>
>>>>
>
>>>> How do you intend to use the "faster" quantity sub-types, currently
>
>>>> all returned by factory methods in AbstractQuantity?
>
>>>> The "Amount" type like e.g. that in ICU4J (there it is named Measure,
>
>>>> but unlike JSR 363 it does not separate between API and implementation,
>
>>>> so
>
>>>> everything are classes) holds a Number, so in theory using different
>
>>>> concrete number sub-classes would work for
>
>>>> Amount.of(100d, SI.METRE) as opposed to
>
>>>> Amount.of(BigDecimal.TEN, SI.METRE) could handle that all.
>
>>>>
>
>>>> What about alternate classes with a lower footprint, especially in SE?
>
>>>> Actually they might matter more, but if using objects like Double,
>
>>>> Integer
>
>>>> or Long worked equally well under ME, we could and should keep that in
>
>>>> sync, with the exception of BigDecimal/BigInteger[?]
>
>>>>
>
>>>> Martin, others WDYT?
>
>>>>
>
>>>> Regards,
>
>>>> Werner
>
>>>>
>
>>>> On Mon, Sep 15, 2014 at 9:07 PM, Otávio Gonçalves de Santana <
>
>>>>
>
>
>>>> wrote:
>
>>>>
>
>>>>> Amount.of() sounds good.
>
>>>>> On Sep 15, 2014 4:04 PM, "Legrand, Karen"
>
>>>>> <
>
>
>>>>> wrote:
>
>>>>>
>
>>>>>> -1 for QuantityAmount. It looks very odd to have two nouns that
>
>>>>>> are essentially synonyms together like that. I think it would be much
>
>>>>>> better to use either ‘Quantity’ or ‘Amount’ by itself.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> *From:* Leonardo Lima
>
>>>>>> [mailto:
]
>
>>>>>> *Sent:* Monday, September 15, 2014 10:44 AM
>
>>>>>> *To:*
>
>>>>>>
>
>>>>>> *Subject:* Re: AbstractQuantity's class
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> QuantityAmount sounds redundant, doesn't it?
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> On Sun, Sep 14, 2014 at 9:03 PM, Otávio Gonçalves de Santana <
>
>>>>>>
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>> Actually I would like to work this and in Lambda expressions.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> Could be QuantityAmount then?
>
>>>>>>
>
>>>>>> anyone?
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> On Sun, Sep 14, 2014 at 6:06 PM, Werner Keil
>
>>>>>> <
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>> Since we drop the .org domain soon, I would not call that UOMo (the
>
>>>>>> Eclipse project certainly will keep the name, after all it also
>
>>>>>> support
>
>>>>>> UCUM which has another .org domain, too)
>
>>>>>>
>
>>>>>> Why would Quantities get an of() method? What would be imaginable is
>
>>>>>> some sort of factory/facade in RI or SE, but except a
>
>>>>>> getInstance(Length.class) similar to the current QuantityFactory class
>
>>>>>> (it's a singleton returning exactly one instance here, see MEEP or
>
>>>>>> CLDC8,
>
>>>>>> they also use both of() and getInstance() for each purpose, just like
>
>>>>>> Josh
>
>>>>>> Bloch explained) there is nothing to be of() in this case.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> QuantityAmount sounds like a good alternative of these, let's see at
>
>>>>>> JavaOne, probably in Hackergarten what's best.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> On Sun, Sep 14, 2014 at 9:01 PM, Otávio Gonçalves de Santana <
>
>>>>>>
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>> I am not referring if the classe be or not be abstract or design,
>
>>>>>> but just the name, I am talking about the nomenclature.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> Could be a good name:
>
>>>>>>
>
>>>>>> - UOMO.of(...)
>
>>>>>>
>
>>>>>> another one is:
>
>>>>>>
>
>>>>>> - Quantities.of(...)
>
>>>>>>
>
>>>>>> or the classic:
>
>>>>>>
>
>>>>>> - QuantityAmount.of(...)
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> On Sun, Sep 14, 2014 at 2:51 PM, Werner Keil
>
>>>>>> <
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>> Sorry, no more Measurable, please
>
>>>>>>
>
>>>>>> We've been there once.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> You bet Spring was probably created a while ago and may not follow
>
>>>>>> all patterns we may see now
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> Something else e.g. QuantityAmount<Q extends Quantity> extends
>
>>>>>> AbstractQuantity<Q> is worth considering, like in UOMo.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> And the subsequent of() methods may be on such a concrete class.
>
>>>>>>
>
>>>>>> If you look at let's say the Collections API, it shows a similar
>
>>>>>> pattern of
>
>>>>>>
>
>>>>>> Interface > AbstractBaseClass > ConcreteClass.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> This "author" may not have done everything consistently there, see
>
>>>>>> EnumSet, but other than that it is still a better piece of API than
>
>>>>>> let's
>
>>>>>> say 310 with hundreds of methods on final classes that are largely
>
>>>>>> incompatible and a TemporalAmount which actually should be called
>
>>>>>> TemporalAmounts, TemporalAmountCollection or whatever
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> On Sun, Sep 14, 2014 at 8:32 AM, Werner Keil
>
>>>>>> <
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>> Sorry but we had that confusion with JSR 275, so ONE Measurement is
>
>>>>>> enough, we must not have Measure implements Measurement, that would
>
>>>>>> just be
>
>>>>>> a mess.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> JScience called that "Amount", but you see a lot of very popular
>
>>>>>> projects (SpringFramework) doing exactly the same. There are
>
>>>>>> Abstract*.valueOf() or similar constructions.
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> Regards,
>
>>>>>>
>
>>>>>> Werner
>
>>>>>>
>
>>>>>>
>
>>>>>> Werner Keil | JCP Executive Committee Member, JSR 363 Co Spec
>
>>>>>> Lead | Eclipse UOMo Lead, Babel Language Champion | Apache
>
>>>>>> Committer | Java Godfather
>
>>>>>>
>
>>>>>> Twitter @wernerkeil | @UnitAPI | @JSR354 | #EclipseUOMo | #Java_Social
>
>>>>>> | #DevOps
>
>>>>>>
>
>>>>>> Skype werner.keil | Google+ gplus.to/wernerkeil
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> * JavaZone 2014: 9-11 Sep 2014, Oslo, Norway. Werner Keil, JCP EC
>
>>>>>> Member, JSR 363 Spec Lead will present "JSR 363 - The Answer to
>
>>>>>> Life Science and the Internet of Everything"
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> * JavaOne 2014: Sep 30, San Francisco, USA, Werner Keil, JCP EC
>
>>>>>> Member, JSR 354 EG Member will host "Java and Digital Currencies,
>
>>>>>> Friend or
>
>>>>>> FOE"
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> * JMaghreb 3.0: 4-6 Nov 2014, Casablanca, Morocco. Werner Keil, JCP
>
>>>>>> EC Member, JSR 363 Spec Lead, DevOps Guy will present "Triple-E'
>
>>>>>> class DevOps", "JSR 363"
>
>>>>>>
>
>>>>>> * ApacheCon Europe: 17 Nov 2014, Budapest, Hungary. Werner Keil, JCP
>
>>>>>> EC Member, Apache DeviceMap Committer will present "Apache DeviceMap
>
>>>>>> "
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> * Mobile Developer Conference kompakt: 18 Nov 2014, Hamburg,
>
>>>>>> Germany. Werner Keil, JCP EC Member, Apache DeviceMap Committer will
>
>>>>>> present "Apache DeviceMap" (GER)
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> On Sun, Sep 14, 2014 at 12:29 PM, Otávio Gonçalves de Santana <
>
>>>>>>
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>> Hi Guys.
>
>>>>>>
>
>>>>>> How is going?
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> I believe we have a possible problem with nomeclature in
>
>>>>>> AbstractQuantity's class, looking this example:
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> Quantity<Length> metre = AbstractQuantity.of(10, SI.METRE);
>
>>>>>>
>
>>>>>> Quantity<Length> foot = metre.to(US.FOOT);
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> IMHO, Abstract* is not a good name to a factory, maybe just Measure,
>
>>>>>> so will:
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> Quantity<Length> metre = Meansure.of(10, SI.METRE);
>
>>>>>>
>
>>>>>> Quantity<Length> foot = metre.to(US.FOOT);
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> WDYF?
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> --
>
>>>>>>
>
>>>>>> Otávio Gonçalves de Santana
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>
>
>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>
>
>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>
>
>>>>>> 55 (11) 98255-3513
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> --
>
>>>>>>
>
>>>>>> Otávio Gonçalves de Santana
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>
>
>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>
>
>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>
>
>>>>>> 55 (11) 98255-3513
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> --
>
>>>>>>
>
>>>>>> Otávio Gonçalves de Santana
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>
>
>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>
>
>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>
>
>>>>>> 55 (11) 98255-3513
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> --
>
>>>>>>
>
>>>>>> Otávio Gonçalves de Santana
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>
>
>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>
>
>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>
>
>>>>>> 55 (11) 98255-3513
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>>
>
>>>>>
>
>>>>
>
>>>
>
>>>
>
>>> --
>
>>> It is not the strongest of the species that survives, nor the most
>
>>> intelligent. It is the one that is most adaptable to change. - Darwin's
>
>>> Origin of Species (digest)
>
>>>
>
>>
>
>>
>
>
>
>
>
--
>
It is not the strongest of the species that survives, nor the most
>
intelligent. It is the one that is most adaptable to change. - Darwin's
>
Origin of Species (digest)
>



Attachment:
329.gif
Description: GIF image
Attachment:
347.gif
Description: GIF image