Well, I had intended to write a JodaHelpers trait that is the same as Helpers except with JodaTimeHelpers and JodaTimeFormats replacing TimeHelpers and TimeFormats, respectively. The main reason is that I would like to have the time DSL be based on Periods instead of millisecond durations, and with TimeHelpers already in scope there would be ambiguous implicit conversions from Long/Int to TimeSpan or Period. Supposedly, 2.8 will have some support for masking or overriding implicits, but I don't want to rely on that in the short term. If a JodaHelpers trait that would replace a Helpers import isn't OK then I can just do this in my own repo.
Thanks, Derek On Fri, Oct 23, 2009 at 2:52 PM, David Pollak <feeder.of.the.be...@gmail.com > wrote: > > > On Wed, Oct 21, 2009 at 7:20 AM, Derek Chen-Becker > <dchenbec...@gmail.com>wrote: > >> It sounds like you're pretty set against making separate impl traits and >> would prefer just putting things directly on TimeHelper. I'm OK with that, >> but I would really like to add a lift-joda module that contains the >> JodaHelpers, JodaTimeFormats and JodaTimeHelpers traits as I would like to >> use them. I should be able to delegate a good chunk of the methods to >> TimeHelpers.jt*, so there shouldn't be any *redundant* code. Is that a >> reasonable compromise? >> > > Yes, as long as import Helpers._ is not incompatible with importing > whatever trait you come up with. > > >> >> Derek >> >> >> On Tue, Oct 20, 2009 at 11:35 PM, Derek Chen-Becker < >> dchenbec...@gmail.com> wrote: >> >>> I agree that the goal isn't to remove java.util.Date. For trivial time >>> handling it works just fine. What I'm trying to achieve here is a way to >>> make Joda Time be the default impl while leaving the user a choice. By using >>> separate traits instead of different names on the same trait, we achieve a >>> few things: >>> >>> 1. A consistent API for both java.util and Joda Time in terms of >>> method names. As Naftoli pointed out, people expect naming of functions >>> consistent with what they do and having two different "now"s on the same >>> trait is going to look a little strange to people, I think. >>> 2. A clean *optional* usage of Joda Time. If we put code that >>> utilizes Joda Time directly into TimeHelpers then it's not an optional >>> dependency. Making a separate trait means that if someone doesn't use the >>> Joda Time trait then they don't need to have the Joda Time jar in their >>> classpath and they never know that it's not there. >>> 3. A relatively simple code change path to move from java.util to >>> Joda Time by simply changing imports. >>> >>> Your assertion that Date is a simple wrapper for a Long timestamp is >>> pretty accurate, but really Joda Time's DateTime is a superset of >>> *Calendar*, not Date. Just look at what we had to do with CalendarExtension >>> to get some simple date manipulation functions, where those same methods are >>> already defined on DateTime. The vast majority of Joda Time's classes are >>> immutable, and the mutators return new instances instead of modifying the >>> current instance. TimeSpan's current handling of duration addition doesn't >>> cope with DST, which I'm sure will show up as a bug in someone's code if it >>> hasn't already. Having done a fair amount of java.util.Date handling and >>> then moving to Joda Time, I find it hard to call the difference between the >>> two APIs "marginal". In any case, I still feel that my proposal makes Joda >>> Time available in a nicer way while leaving existing code completely >>> untouched (by introducing a JodaHelpers trait that mirrors Helpers). >>> >>> Derek >>> >>> >>> On Tue, Oct 20, 2009 at 9:25 PM, David Pollak < >>> feeder.of.the.be...@gmail.com> wrote: >>> >>>> >>>> >>>> On Tue, Oct 20, 2009 at 6:56 PM, Naftoli Gugenheim < >>>> naftoli...@gmail.com> wrote: >>>> >>>>> >>>>> I agree with this. >>>>> My understanding is that the goal is that Lift should use Joda for its >>>>> time functions rather than java.util. >>>> >>>> >>>> This is not the goal. The goal is to make JodeTime available. There is >>>> no reason to remove support for java.util.Date. None. >>>> >>>> JodaTime offers some advantages, but there's no reason, none, nada, to >>>> *remove* support for java.util.Date. >>>> >>>> I'm cool with different names (not jtNow, but choose something else). >>>> >>>> But I view removal of support for java.util.Date as gratuitous. Sure, >>>> if we were to make the clean-slate decision today, I'd opt for primary >>>> support of JodaTime and secondary support for java.util.Date. But we're >>>> making a decision based on legacy. We're not going to cut off >>>> java.util.Date just because something marginally better (and I'm not >>>> being facetious here... at the bottom, these are just wrappers for number >>>> of >>>> milliseconds since Jan 1, 1970). >>>> >>>> >>>>> If the Joda methods have different and longer names, then it's existing >>>>> side by side with the java.util implementation, not replacing it. >>>>> To many people, it is important that methods etc. should be named >>>>> properly and aesthetically. It's not pleasant to use names like "jtNow" in >>>>> your code when that is the method that gets used normally. Sure, if 'now' >>>>> was the usual method and a 'jtNow' method was called in special >>>>> circumstances, it's an understandable name. But names that are used in >>>>> ordinary circumstances should have straightforward names. >>>>> (Names should be concise expressions of what they represent. This aids >>>>> in memorization and code readability.) >>>>> Also, it will be impossible to deprecate the java.util implementation >>>>> and have a clean API instead. If we use separate traits with the same >>>>> method >>>>> names, then we will be able to. >>>>> >>>>> >>>>> ------------------------------------- >>>>> Derek Chen-Becker<dchenbec...@gmail.com> wrote: >>>>> >>>>> On Tue, Oct 20, 2009 at 4:59 PM, David Pollak < >>>>> feeder.of.the.be...@gmail.com >>>>> > wrote: >>>>> >>>>> > What I checked in allows you to use JodaTime just as easily (well >>>>> with 2 >>>>> > extra characters in a few method names) as java.util.Date. How is >>>>> anything >>>>> > more "default" than that? >>>>> > >>>>> >>>>> My primary concern with this approach is that it makes changing between >>>>> the >>>>> two implementations something that requires a global search and replace >>>>> on >>>>> one or more method names, whereas having two different implementation >>>>> traits >>>>> means that generally I should be able to just change the import and the >>>>> code >>>>> will work. A secondary (minor) concern is that having method names >>>>> reflect >>>>> the underlying implementation details goes against my aesthetics. >>>>> >>>>> >>>>> > It's an interesting difference between an OO vs. non-OO. In the >>>>> > implementation I created, there choice of one or the other is made >>>>> based on >>>>> > singleton methods invoked. This allows mixing both in the same code >>>>> simply >>>>> > by invoking now or jtNow. >>>>> > >>>>> >>>>> I would argue that it's not a common case where you would want to use >>>>> both >>>>> libraries, particularly when Joda's DateTime has an explicit toDate on >>>>> it >>>>> that returns a java.util.Date. There are similar methods to return >>>>> Calendar >>>>> and TimeZone instances as needed. These are simple methods to use >>>>> directly, >>>>> or it's easy to create a view that handles this automatically. >>>>> >>>>> I'm unclear why this is not possible. We can add a DSL for >>>>> manipulating >>>>> > JodaTime without breaking anything we have. The TimeSpan class >>>>> simply gets >>>>> > enhanced to deal with additional stuff and maybe uses JodaTime under >>>>> the >>>>> > covers. >>>>> > >>>>> >>>>> The underpinning of the current DSL is the TimeSpan class. Joda Time >>>>> already >>>>> has a time interval class corresponding to TimeSpan called Duration, >>>>> but the >>>>> more proper class to use is actually Period. Period is premised not on >>>>> ms >>>>> duration but rather on field deltas, which allows it to properly handle >>>>> DST. >>>>> Modifying the current DSL to work for Duration and Period via TimeSpan >>>>> is >>>>> just going to end up with a lot of redundant code, when a Joda-only DSL >>>>> would be cleaner and more in line with how you would want to use Joda >>>>> Time. >>>>> >>>>> >>>>> > They have that now with the implementation I did on your branch. >>>>> > >>>>> >>>>> Like I said before, I have a strong preference for the OO approach and >>>>> being >>>>> able to change impls by changing the import rather than having to >>>>> change >>>>> methods all over the place. If you really feel strongly that we can't >>>>> have a >>>>> separate trait in Lift, I can just create a different artifact in my >>>>> own >>>>> repo that tracks Lift and create the JodaHelpers, JodaTimeFormats and >>>>> JodaTimeHelpers traits there. >>>>> >>>>> Cheers, >>>>> >>>>> Derek >>>>> >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> Lift, the simply functional web framework http://liftweb.net >>>> Beginning Scala http://www.apress.com/book/view/1430219890 >>>> Follow me: http://twitter.com/dpp >>>> Surf the harmonics >>>> >>>> >>>> >>> >> >> >> > > > -- > Lift, the simply functional web framework http://liftweb.net > Beginning Scala http://www.apress.com/book/view/1430219890 > Follow me: http://twitter.com/dpp > Surf the harmonics > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Lift" group. 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