From 6dc8a6a5df5e2dc30d78a4f0fd637eed417b08a1 Mon Sep 17 00:00:00 2001
From: Miles Sabin <miles@milessabin.com>
Date: Tue, 3 Jun 2014 07:00:17 +0100
Subject: [PATCH] Allow primes at the end of identifiers.

---
 .../scala/tools/nsc/ast/parser/Scanners.scala | 11 +++++
 .../scala/reflect/NameTransformer.scala       |  1 +
 test/files/neg/primed-identifiers.check       |  7 +++
 test/files/neg/primed-identifiers.scala       | 13 +++++
 test/files/pos/primed-identifiers.scala       | 48 +++++++++++++++++++
 5 files changed, 80 insertions(+)
 create mode 100644 test/files/neg/primed-identifiers.check
 create mode 100644 test/files/neg/primed-identifiers.scala
 create mode 100644 test/files/pos/primed-identifiers.scala

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index 328c10448b2..a5fa90bacac 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -637,6 +637,10 @@ trait Scanners extends ScannersCommon {
         putChar(ch)
         nextChar()
         getIdentOrOperatorRest()
+      case '\'' =>
+        putChar(ch)
+        nextChar()
+        getPrimeRest()
       case SU => // strangely enough, Character.isUnicodeIdentifierPart(SU) returns true!
         finishNamed()
       case _ =>
@@ -649,6 +653,13 @@ trait Scanners extends ScannersCommon {
         }
     }
 
+    private def getPrimeRest(): Unit =
+      if (ch == '\'') {
+        putChar(ch)
+        nextChar()
+        getPrimeRest()
+      } else finishNamed()
+
     private def getOperatorRest(): Unit = (ch: @switch) match {
       case '~' | '!' | '@' | '#' | '%' |
            '^' | '*' | '+' | '-' | '<' |
diff --git a/src/library/scala/reflect/NameTransformer.scala b/src/library/scala/reflect/NameTransformer.scala
index a8430548f5c..864ac3cfc72 100755
--- a/src/library/scala/reflect/NameTransformer.scala
+++ b/src/library/scala/reflect/NameTransformer.scala
@@ -54,6 +54,7 @@ object NameTransformer {
   enterOp('\\', "$bslash")
   enterOp('?', "$qmark")
   enterOp('@', "$at")
+  enterOp('\'', "$prime")
 
   /** Replace operator symbols by corresponding `\$opname`.
    *
diff --git a/test/files/neg/primed-identifiers.check b/test/files/neg/primed-identifiers.check
new file mode 100644
index 00000000000..fa4fb81daf6
--- /dev/null
+++ b/test/files/neg/primed-identifiers.check
@@ -0,0 +1,7 @@
+primed-identifiers.scala:4: error: value b' is not a member of object a1
+  a1 b'c' // parses as a1 b' c'
+     ^
+primed-identifiers.scala:4: error: not found: value c'
+  a1 b'c' // parses as a1 b' c'
+       ^
+two errors found
diff --git a/test/files/neg/primed-identifiers.scala b/test/files/neg/primed-identifiers.scala
new file mode 100644
index 00000000000..68c2876bfe9
--- /dev/null
+++ b/test/files/neg/primed-identifiers.scala
@@ -0,0 +1,13 @@
+object a1 {
+  def b(c: Char) = ???
+
+  a1 b'c' // parses as a1 b' c'
+}
+
+object a2 {
+   def b'(c: Int) = ???
+   def b(c: Char) = ???
+
+  val c' = 23
+  a2 b'c' // parses as a2 b' c'
+}
diff --git a/test/files/pos/primed-identifiers.scala b/test/files/pos/primed-identifiers.scala
new file mode 100644
index 00000000000..348ff4aca20
--- /dev/null
+++ b/test/files/pos/primed-identifiers.scala
@@ -0,0 +1,48 @@
+object Test {
+  val l = List("Identifiers", "with", "primes", "!")
+
+  val l' = l map(_.length)
+
+  val l'' = l zip l'
+
+  val l''' = l''.reverse
+
+  object a1 {
+    def b(c: Char) = ???
+
+    a1 b 'c'
+  }
+
+  object a2 {
+    def b'(c: Int) = ???
+    def b(c: Char) = ???
+
+    a2 b' 23
+    a2 b'23
+
+    val i = 23
+    a2 b'i
+
+    val c' = 23
+    a2 b'c' // parses as a2 b' c'
+
+    a2 b 'c'
+  }
+
+  case object Foo'
+  case class Bar'(i: Int)
+
+  ((): Any) match {
+    case foo': String => ???
+    case Foo' => ???
+    case Bar'(foo') => ???
+  }
+
+  val (x', y') = (13, 23)
+
+  for (z' <- List(x', y')) x'*2
+
+  type T' = Int
+  def foo[U', F'[_]](ft: F'[T'], fu: F'[U']) = (ft, fu)
+}
+