Implicits to encourage more Name-dropping.

This creates implicits in cakes across the land from:

  String => TermName
  String => TypeName

And also from:

  Name => NameOps[Name]           // lower priority
  TermName => NameOps[TermName]
  TypeName => NameOps[TypeName]

What this is all about, using "drop" as a motivating example,
is that these should all work:

  "abc" drop 1                      // "bc": String
  ("abc": TermName) drop 1          // "bc": TermName
  ("abc": TypeName) drop 1          // "bc": TypeName
  (("abc": TypeName): Name) drop 1  // "bc": Name

But this should not:

  ("bc": Name)  // ambiguity error

This requires drop not being directly on Name; peer implicits
from String => TermName and String => TypeName; implicit
classes to install drop on TermName and TypeName; and a lower
priority implicit class to allow ops on Names.

Review by @xeno.by .

4 files changed, 35 insertions, 0 deletions

diff --git a/test/files/neg/reflection-names-neg.check b/test/files/neg/reflection-names-neg.check
new file mode 100644
index 0000000000..a56a19e7fd
--- /dev/null
+++ b/test/files/neg/reflection-names-neg.check
@@ -0,0 +1,10 @@
+reflection-names-neg.scala:5: error: type mismatch;
+ found   : String("abc")
+ required: reflect.runtime.universe.Name
+Note that implicit conversions are not applicable because they are ambiguous:
+ both method stringToTermName in trait Names of type (s: String)reflect.runtime.universe.TermName
+ and method stringToTypeName in trait Names of type (s: String)reflect.runtime.universe.TypeName
+ are possible conversion functions from String("abc") to reflect.runtime.universe.Name
+  val x2 = ("abc": Name) drop 1         // error
+            ^
+one error found
diff --git a/test/files/neg/reflection-names-neg.scala b/test/files/neg/reflection-names-neg.scala
new file mode 100644
index 0000000000..7283d16db9
--- /dev/null
+++ b/test/files/neg/reflection-names-neg.scala
@@ -0,0 +1,6 @@
+import scala.reflect.runtime.universe._
+
+object Test {
+  val x1 = "abc" drop 1                 // "bc": String
+  val x2 = ("abc": Name) drop 1         // error
+}
diff --git a/test/files/run/reflection-names.check b/test/files/run/reflection-names.check
new file mode 100644
index 0000000000..f8cb78cc67
--- /dev/null
+++ b/test/files/run/reflection-names.check
@@ -0,0 +1,4 @@
+(java.lang.String,bc)
+(scala.reflect.internal.Names$TermName_R,bc)
+(scala.reflect.internal.Names$TypeName_R,bc)
+(scala.reflect.internal.Names$TypeName_R,bc)
diff --git a/test/files/run/reflection-names.scala b/test/files/run/reflection-names.scala
new file mode 100644
index 0000000000..2433c84813
--- /dev/null
+++ b/test/files/run/reflection-names.scala
@@ -0,0 +1,15 @@
+import scala.tools.nsc._
+
+object Test {
+  val global = new Global(new Settings())
+  import global._
+
+  val x1 = "abc" drop 1                      // "bc": String
+  val x2 = ("abc": TermName) drop 1          // "bc": TermName
+  val x3 = ("abc": TypeName) drop 1          // "bc": TypeName
+  val x4 = (("abc": TypeName): Name) drop 1  // "bc": Name
+
+  def main(args: Array[String]): Unit = {
+    List(x1, x2, x3, x4) foreach (x => println(x.getClass.getName, x))
+  }
+}