String interpolation added as experimental feat...

String interpolation added as experimental feature. Review by extempore.

1 files changed, 27 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
index 8955537345..787dde541d 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
@@ -9,7 +9,7 @@
 package scala.tools.nsc
 package ast.parser
 
-import scala.collection.mutable.ListBuffer
+import scala.collection.mutable.{ListBuffer, StringBuilder}
 import util.{ SourceFile, OffsetPosition, FreshNameCreator }
 import scala.reflect.internal.{ ModifierFlags => Flags }
 import Tokens._
@@ -616,8 +616,8 @@ self =>
 
     def isLiteralToken(token: Int) = token match {
       case CHARLIT | INTLIT | LONGLIT | FLOATLIT | DOUBLELIT |
-           STRINGLIT | SYMBOLLIT | TRUE | FALSE | NULL          => true
-      case _                                                    => false
+           STRINGLIT | STRINGPART | SYMBOLLIT | TRUE | FALSE | NULL => true
+      case _                                                        => false
     }
     def isLiteral = isLiteralToken(in.token)
 
@@ -1109,6 +1109,8 @@ self =>
       }
       if (in.token == SYMBOLLIT)
         Apply(scalaDot(nme.Symbol), List(finish(in.strVal)))
+      else if (in.token == STRINGPART)
+        interpolatedString()
       else finish(in.token match {
         case CHARLIT               => in.charVal
         case INTLIT                => in.intVal(isNegated).toInt
@@ -1125,6 +1127,27 @@ self =>
       })
     }
 
+    private def stringOp(t: Tree, op: TermName) = {
+      val str = in.strVal
+      in.nextToken()
+      if (str.isEmpty) t
+      else atPos(t.pos.startOrPoint) {
+        Apply(Select(t, op), List(Literal(Constant(str))))
+      }
+    }
+
+    private def interpolatedString(): Tree = {
+      var t = atPos(o2p(in.offset))(New(TypeTree(definitions.StringBuilderClass.tpe), List(List())))
+      while (in.token == STRINGPART) {
+        t = stringOp(t, nme.append)
+        var e = expr()
+        if (in.token == STRINGFMT) e = stringOp(e, nme.formatted)
+        t = atPos(t.pos.startOrPoint)(Apply(Select(t, nme.append), List(e)))
+      }
+      if (in.token == STRINGLIT) t = stringOp(t, nme.append)
+      atPos(t.pos)(Select(t, nme.toString_))
+    }
+
 /* ------------- NEW LINES ------------------------------------------------- */
 
     def newLineOpt() {
@@ -1812,7 +1835,7 @@ self =>
             in.nextToken()
             atPos(start, start) { Ident(nme.WILDCARD) }
           case CHARLIT | INTLIT | LONGLIT | FLOATLIT | DOUBLELIT |
-               STRINGLIT | SYMBOLLIT | TRUE | FALSE | NULL =>
+               STRINGLIT | STRINGPART | SYMBOLLIT | TRUE | FALSE | NULL =>
             atPos(start) { literal(false) }
           case LPAREN =>
             atPos(start)(makeParens(noSeq.patterns()))