Merge pull request #1194 from scalamacros/ticket/6281

SI-6281 macroArgs for defs with implicit args

4 files changed, 65 insertions, 0 deletions

diff --git a/test/files/run/macro-expand-implicit-argument.check b/test/files/run/macro-expand-implicit-argument.check
new file mode 100644
index 0000000000..fb42345748
--- /dev/null
+++ b/test/files/run/macro-expand-implicit-argument.check
@@ -0,0 +1 @@
+List(1, 2, 3)

diff --git a/test/files/run/macro-expand-implicit-argument.flags b/test/files/run/macro-expand-implicit-argument.flags
new file mode 100644
index 0000000000..cd66464f2f
--- /dev/null
+++ b/test/files/run/macro-expand-implicit-argument.flags
@@ -0,0 +1 @@
+-language:experimental.macros
\ No newline at end of file
diff --git a/test/files/run/macro-expand-implicit-argument/Macros_1.scala b/test/files/run/macro-expand-implicit-argument/Macros_1.scala
new file mode 100644
index 0000000000..7629c5a9e2
--- /dev/null
+++ b/test/files/run/macro-expand-implicit-argument/Macros_1.scala
@@ -0,0 +1,59 @@
+import annotation.tailrec
+import scala.math.{min, max}
+import scala.{specialized => spec}
+
+import language.experimental.macros
+
+import scala.reflect.{ClassTag, TypeTag}
+import scala.reflect.macros.Context
+
+object Macros {
+  def alloc[@spec A:ClassTag](src:Array[A], s1:Int, len:Int) = {
+    val as = Array.ofDim[A](len)
+    System.arraycopy(src, s1, as, 0, len)
+    as
+  }
+
+  /**
+   * Efficient alternative to Array.apply.
+   *
+   * "As seen on scala-internals!"
+   */
+  def array[A](as:A*)(implicit ct: ClassTag[A]) = macro arrayMacro[A]
+
+  /**
+   * Takes in something like:
+   *   ArrayUtil.alloc[Int](11, 22, 33, 44)(ct)
+   *
+   * and builds a tree like:
+   *   {
+   *     val arr:Array[Int] = ct.newArray(4)
+   *     arr.update(0, 11)
+   *     arr.update(1, 22)
+   *     arr.update(2, 33)
+   *     arr.update(3, 44)
+   *     arr
+   *   }
+   */
+  def arrayMacro[A:c.AbsTypeTag](c:Context)(as:c.Expr[A]*)(ct: c.Expr[ClassTag[A]]): c.Expr[Array[A]] = {
+    import c.mirror._
+    import c.universe._
+    def const(x:Int) = Literal(Constant(x))
+
+    val n = as.length
+    val arr = newTermName("arr")
+
+    val create = Apply(Select(ct.tree, "newArray"), List(const(n)))
+    val arrtpe = TypeTree(implicitly[c.AbsTypeTag[Array[A]]].tpe)
+    val valdef = ValDef(Modifiers(), arr, arrtpe, create)
+
+    val updates = (0 until n).map {
+      i => Apply(Select(Ident(arr), "update"), List(const(i), as(i).tree))
+    }
+
+    val exprs = Seq(valdef) ++ updates ++ Seq(Ident(arr))
+    val block = Block(exprs:_*)
+
+    c.Expr[Array[A]](block)
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/macro-expand-implicit-argument/Test_2.scala b/test/files/run/macro-expand-implicit-argument/Test_2.scala
new file mode 100644
index 0000000000..ce8a068fb4
--- /dev/null
+++ b/test/files/run/macro-expand-implicit-argument/Test_2.scala
@@ -0,0 +1,4 @@
+object Test extends App {
+  import Macros._
+  println(array(1, 2, 3).toList)
+}
\ No newline at end of file