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Macro annotation extension method
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class ext extends StaticAnnotation { | |
def macroTransform(annottees: Any*) = macro extension.impl | |
} | |
object extension { | |
def impl(c: Context)(annottees: c.Expr[Any]*): c.Expr[Any] = { | |
import c.universe._ | |
annottees.map{ _.tree }.head match { | |
case q"def $name[..$tp](...$params): $ret = $b" => | |
val Seq(Seq(thiz, rest @ _*), rest2 @ _*) = params | |
val rr = rest +: rest2 | |
val term = c.freshName() | |
val term2 = TypeName(term) | |
c.Expr[Any]{ | |
q""" | |
implicit class $term2[..$tp]($thiz) extends AnyVal { | |
def $name(...$rr): $ret = $b | |
} | |
""" | |
} | |
case that => | |
println(that) | |
c.abort(c.enclosingPosition, that.toString) | |
} | |
} | |
} |
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import scala.collection.generic.CanBuildFrom | |
/** | |
* Created by arneball on 2014-05-26. | |
*/ | |
object ExtensionMethod extends App with Integral.ExtraImplicits { | |
@ext def add(thiz: Int, that: Int) = thiz + that | |
println{ | |
5 add 5 | |
} | |
@ext def unary_!(thiz: String) = thiz.reverse | |
println{ | |
!"Hello world" | |
} | |
type CB[CC[_], From, Elem] = CanBuildFrom[CC[From], Elem, CC[Elem]] | |
@ext def collPart[T, U, SEQ[x] <: Seq[x]](thiz: SEQ[T], fun: PartialFunction[T, U])(implicit cbf: CB[SEQ, T, T], cb2: CB[SEQ, T, U]): (SEQ[U], SEQ[T]) = { | |
val trues = cb2() | |
val falses = cbf() | |
thiz.foreach{ e => | |
if(fun.isDefinedAt(e)) trues += fun(e) else falses += e | |
} | |
trues.result() -> falses.result() | |
} | |
val (x1, x2) = Vector(1, 2, 3, 4, 5).collPart{ case 2 => "Shit" } | |
println(x1) | |
println(x2) | |
} |
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