I think you’ll get help much faster if you ask this at the *scala-user*mailing
list (tip: put the word “macro” in the topic to summon Eugene
Burmako). Anyway, the code should be something like this:
trait Table {
def columns: List[Column] = macro TableMacros.columnsImpl
}
object TableMacros {
import scala.reflect.macros.Context // on 2.11, see blackbox/whitebox in
the docs
def columnsImpl(c: scala.reflect.macros.Context): c.Expr[List[Column]] = {
import c.universe._
// 1.
// use c.prefix to get the exact class
// try doing println(showRaw(c.prefix)) to see the tree and where the
class goes there
// 2.
// find the column declarations — should be similar to what you have now
// 3.
// return c.Expr[List[Column]](x), where x is your List[Tree], each
Tree corresponds to a column identifier
}
}
HTH,
N
On Friday, May 23, 2014 11:58:25 AM UTC+1, David Pérez wrote:
>
> Thanks Andrzej (it looks like a Poland name).
> I'll take a look at it carefully later.
> This is my exact use case:
>
> http://stackoverflow.com/questions/23752885/how-to-use-reflection-at-compile-time
>
> I'm creating a DSL for simplifying access to SQLite.
> When finished, I'll share via github.
>
>
> Am Freitag, 23. Mai 2014 12:28:11 UTC+2 schrieb Andrzej Giniewicz:
>>
>> It might be not exactly what you need, but we use macros on Android in
>> SpecGine ( game engine my group works on -
>> https://bitbucket.org/specdevs/specgine ). While it isn't maybe the
>> best example, it works good enough for our use case, i.e. we heavily
>> use macro
>>
>> def withManager[T <: ComponentsSpec]: T with ComponentsManager
>>
>> which inspects how T is constructed and mixes in manager instance to
>> use it within our Entity system. It works quite well with macros in
>> 2.10 (SpecGine 0.1) and we still use it with 2.11 after simple porting
>> (current master branch), without macro paradise.
>>
>> What is the problem you are trying to solve? Because reflection can
>> solve many problems, optimal solutions might be different.
>>
>> On Wed, May 21, 2014 at 12:28 PM, David Pérez
>> <[email protected]> wrote:
>> > Does anyone know if reflection at compile time through macros has this
>> kind
>> > of problems?
>>
>>
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