>
>
> On Wed, May 5, 2010 at 9:30 AM, Jorge Ortiz <
[hidden email]> wrote:
>>
>> Huh. I have NO idea.
>
> REPL voodoo?
>
>>
>> --j
>>
>> On Wed, May 5, 2010 at 12:13 AM, Heiko Seeberger
>> <
[hidden email]> wrote:
>>>
>>> Interesting stuff!
>>> Why does this work when using Foo[_] does not?
>>> scala> manifest[Option[_]]
>>> res9: scala.reflect.Manifest[Option[_]] = scala.Option[Any]
>>> Heiko
>>> On 5 May 2010 08:29, Jorge Ortiz <
[hidden email]> wrote:
>>>>
>>>> Yes, you're correct. I see now that ClassManifest captures as much type
>>>> information as it can.
>>>> The difference comes here:
>>>> scala> class Foo[T]
>>>> defined class Foo
>>>> scala> type T = Foo[_]
>>>> defined type alias T
>>>> scala> val m = manifest[T]
>>>> <console>:6: error: could not find implicit value for parameter m:
>>>> Manifest[T]
>>>> val m = manifest[T]
>>>> ^
>>>> scala> val m = classManifest[T]
>>>> m: ClassManifest[T] = Foo[<?>]
>>>> In this case, you can make a ClassManifest[T], but you can't make a
>>>> Manifest[T].
>>>> --j
>>>> On Tue, May 4, 2010 at 10:19 PM, Arjan Blokzijl
>>>> <
[hidden email]> wrote:
>>>>>
>>>>> That's what I understood from the Array SID as well, and the code also
>>>>> seemed to indicate this. However, a brief experiment in the REPL showed
>>>>> this:
>>>>> scala> class Foo[T]
>>>>> defined class Foo
>>>>> scala> class Bar[T]
>>>>> defined class Bar
>>>>> scala> class Baz
>>>>> defined class Baz
>>>>> scala> type T = Foo[Bar[Baz]]
>>>>> defined type alias T
>>>>> scala>val m = manifest[T]
>>>>> m: Manifest[T] = Foo[Bar[Baz]]
>>>>> scala> val cm = classManifest[T]
>>>>> cm: ClassManifest[T] = Foo[Bar[Baz]]
>>>>> scala> m.typeArguments
>>>>> res0: List[scala.reflect.Manifest[_]] = List(Bar[Baz])
>>>>> scala> cm.typeArguments
>>>>> res1: List[scala.reflect.OptManifest[_]] = List(Bar[Baz])
>>>>> scala> cm == m
>>>>> res2: Boolean = true
>>>>> scala> cm.isInstanceOf[Manifest[_]]
>>>>> res3: Boolean = false
>>>>> scala> m.isInstanceOf[Manifest[_]]
>>>>> res4: Boolean = true
>>>>> scala> cm.isInstanceOf[ClassManifest[_]]
>>>>> res5: Boolean = true
>>>>>
>>>>> Perhaps I'm doing the completely wrong experiment here, but at first
>>>>> sight the ClassManifest also seems to contain all type arguments.
>>>>>
>>>>> Arjan
>>>>>
>>>>> On Tue, May 4, 2010 at 7:13 PM, Jorge Ortiz <
[hidden email]>
>>>>> wrote:
>>>>>>
>>>>>> My understand is that if:
>>>>>> type T = Foo[Bar[Baz]]
>>>>>> then Manifest[T] represents the entire Foo[Bar[Baz]] type, whereas
>>>>>> ClassManifest[T] only represents Foo[_].
>>>>>> For instantiating Arrays, you only need to know whether it's a
>>>>>> primitive array or a reference array, so only the ClassManifest is needed.
>>>>>> (But a Manifest is also a ClassManifest...)
>>>>>> --j
>>>>>> On Tue, May 4, 2010 at 12:44 AM, Heiko Seeberger
>>>>>> <
[hidden email]> wrote:
>>>>>>>
>>>>>>> Hi,
>>>>>>> could someone please explain the difference between ClassManifest and
>>>>>>> Manifest? And when to use which one?
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Heiko
>>>>>>>
>>>>>>> Company: weiglewilczek.com
>>>>>>> Blog: heikoseeberger.name
>>>>>>> Follow me: twitter.com/hseeberger
>>>>>>> OSGi on Scala: scalamodules.org
>>>>>>> Lift, the simply functional web framework: liftweb.net
>>>>>>> Stambecco, highly scalable computing: stambecco.org
>>>>>>
>>>>>
>>>>
>>>
>>>
>>>
>>> --
>>> Heiko Seeberger
>>>
>>> Company: weiglewilczek.com
>>> Blog: heikoseeberger.name
>>> Follow me: twitter.com/hseeberger
>>> OSGi on Scala: scalamodules.org
>>> Lift, the simply functional web framework: liftweb.net
>>> Stambecco, highly scalable computing: stambecco.org
>>
>
>
>
> --
> Viktor Klang
> | "A complex system that works is invariably
> | found to have evolved from a simple system
> | that worked." - John Gall
>
> Akka - the Actor Kernel: Akkasource.org
> Twttr: twitter.com/viktorklang
>
Locked
