Refining the previous to only apply to symbolic methods, not quoted, standard or op-suffix method names

Author: Lucy Martin

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -814,8 +814,8 @@ object Parsers {
      *   6. the opening brace does not follow a `=>`. The reason for this condition is that
      *      rewriting back to braces does not work after `=>` (since in most cases braces are omitted
      *      after a `=>` it would be annoying if braces were inserted).
-     *   7. not a code block being the input to a direct function call `inst method {\n expr \n}` cannot become
-     *      `inst method :\n expr`
+     *   7. not a code block being the input to a direct symbolic function call `inst method {\n expr \n}` cannot
+     *      become `inst method :\n expr` for a fully symbolic method
      */
     def bracesToIndented[T](body: => T, rewriteWithColon: Boolean): T = {
       val underColonSyntax = possibleColonOffset == in.lastOffset
@@ -830,16 +830,24 @@ object Parsers {
       var canRewrite = allBraces(in.currentRegion) && // test (1)
         !testChars(in.lastOffset - 3, " =>") // test(6)
 
-      def isStartOfFunction: Boolean =
-        opStack.headOption.exists(x => x.offset > startOpening && x.offset < endOpening)
+      def isStartOfSymbolicFunction: Boolean =
+        opStack.headOption.exists { x =>
+          val bq = x.operator.isBackquoted
+          val op = x.operator.name.toSimpleName.decode.forall {
+            Chars.isOperatorPart
+          }
+          val loc = startOpening < x.offset && x.offset < endOpening
+          val res = !bq && op && loc
+          res
+        }
       val t = enclosed(LBRACE, {
         canRewrite &= in.isAfterLineEnd // test (2)
         val curOffset = in.offset
         try {
           val bodyResolved = body
           bodyResolved match
             case x:(Match | Block) =>
-              canRewrite &= !isStartOfFunction // test (7)
+              canRewrite &= !isStartOfSymbolicFunction // test (7)
             case _ =>
           bodyResolved
         }

tests/rewrites/i20002.check

@@ -5,6 +5,18 @@ object Reactions:
       case 1 =>
     }
 
+    Reactions run:
+      case 0 =>
+      case 1 =>
+
+    Reactions run_+ :
+      case 0 =>
+      case 1 =>
+
+    Reactions `+=`:
+      case 0 =>
+      case 1 =>
+
     def bar: Int = ???
 
     bar match
@@ -27,6 +39,13 @@ object Reactions:
     Reactions += {
       partialFunction
     }
+
   def +=(f: PartialFunction[Int, Unit]) =
     ???
 
+  def run (f: PartialFunction[Int, Unit]) =
+    ???
+
+  def run_+ (f: PartialFunction[Int, Unit]) =
+    ???
+

tests/rewrites/i20002.scala

@@ -5,6 +5,21 @@ object Reactions {
       case 1 =>
     }
 
+    Reactions run {
+      case 0 =>
+      case 1 =>
+    }
+
+    Reactions run_+ {
+      case 0 =>
+      case 1 =>
+    }
+
+    Reactions `+=` {
+      case 0 =>
+      case 1 =>
+    }
+
     def bar: Int = ???
 
     bar match {
@@ -31,8 +46,17 @@ object Reactions {
       partialFunction
     }
   }
+
   def +=(f: PartialFunction[Int, Unit]) = {
     ???
   }
 
+  def run (f: PartialFunction[Int, Unit]) = {
+    ???
+  }
+
+  def run_+ (f: PartialFunction[Int, Unit]) = {
+    ???
+  }
+
 }