Remove operator position attachment

- simplify select name span logic
- add test for left associative operators

Author: Kordyjan

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -39,9 +39,6 @@ object desugar {
    */
   val MultiLineInfix: Property.Key[Unit] = Property.StickyKey()
 
-  /** An attachment for retaining information about the original span of the operator after desugaring it to Select. */
-  val OperatorSpan: Property.Key[Span] = Property.StickyKey()
-
   /** What static check should be applied to a Match? */
   enum MatchCheck {
     case None, Exhaustive, IrrefutablePatDef, IrrefutableGenFrom
@@ -1218,7 +1215,7 @@ object desugar {
       case _ => arg
     }
     def makeOp(fn: Tree, arg: Tree, selectPos: Span) =
-      val sel = Select(fn, op.name).withSpan(selectPos).withAttachment(OperatorSpan, op.span)
+      val sel = Select(fn, op.name).withSpan(selectPos)
       if (left.sourcePos.endLine < op.sourcePos.startLine)
         sel.pushAttachment(MultiLineInfix, ())
       arg match

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -419,10 +419,13 @@ object Trees {
     def nameSpan(using Context): Span =
       if span.exists then
         val point = span.point
-        getAttachment(desugar.OperatorSpan) match
-          case Some(s) => s
-          case None if span.isSynthetic || name.toTermName == nme.ERROR => Span(point)
-          case None => Span(point, span.end, point)
+        if name.toTermName == nme.ERROR then
+          Span(point)
+        else if qualifier.span.start > span.start then // right associative
+          val realName = name.stripModuleClassSuffix.lastPart
+          Span(span.start, span.start + realName.length, point)
+        else
+          Span(point, span.end, point)
       else span
   }
 

tests/semanticdb/expect/Extension.expect.scala

@@ -1,6 +1,9 @@
 package ext
 
-/*<-ext::Extension$package.*/extension (s/*<-ext::Extension$package.foo().(s)*/: String/*->scala::Predef.String#*/)
+/*<-ext::Extension$package.*/extension (s/*<-ext::Extension$package.foo().(s)*//*<-ext::Extension$package.`#*#`().(s)*/: String/*->scala::Predef.String#*/)
   def foo/*<-ext::Extension$package.foo().*/: Int/*->scala::Int#*/ = 42
+  def #*#/*<-ext::Extension$package.`#*#`().*/ (i/*<-ext::Extension$package.`#*#`().(i)*/: Int/*->scala::Int#*/): (String/*->scala::Predef.String#*/, Int/*->scala::Int#*/) = (/*->scala::Tuple2.apply().*/s/*->ext::Extension$package.`#*#`().(s)*/, i/*->ext::Extension$package.`#*#`().(i)*/)
 
-val a/*<-ext::Extension$package.a.*/ = "asd".foo/*->ext::Extension$package.foo().*/
+val a/*<-ext::Extension$package.a.*/ = "asd".foo/*->ext::Extension$package.foo().*/
+
+val c/*<-ext::Extension$package.c.*/ = "foo" #*#/*->ext::Extension$package.`#*#`().*/ 23

tests/semanticdb/expect/Extension.scala

@@ -2,5 +2,8 @@ package ext
 
 extension (s: String)
   def foo: Int = 42
+  def #*# (i: Int): (String, Int) = (s, i)
 
-val a = "asd".foo
+val a = "asd".foo
+
+val c = "foo" #*# 23

tests/semanticdb/metac.expect

@@ -1112,24 +1112,39 @@ Schema => SemanticDB v4
 Uri => Extension.scala
 Text => empty
 Language => Scala
-Symbols => 4 entries
-Occurrences => 8 entries
+Symbols => 8 entries
+Occurrences => 19 entries
 
 Symbols:
 ext/Extension$package. => final package object ext
+ext/Extension$package.`#*#`(). => method #*#
+ext/Extension$package.`#*#`().(i) => param i
+ext/Extension$package.`#*#`().(s) => param s
 ext/Extension$package.a. => val method a
+ext/Extension$package.c. => val method c
 ext/Extension$package.foo(). => method foo
 ext/Extension$package.foo().(s) => param s
 
 Occurrences:
 [0:8..0:11): ext <- ext/
 [2:0..2:0): <- ext/Extension$package.
 [2:11..2:12): s <- ext/Extension$package.foo().(s)
+[2:11..2:12): s <- ext/Extension$package.`#*#`().(s)
 [2:14..2:20): String -> scala/Predef.String#
 [3:6..3:9): foo <- ext/Extension$package.foo().
 [3:11..3:14): Int -> scala/Int#
-[5:4..5:5): a <- ext/Extension$package.a.
-[5:14..5:17): foo -> ext/Extension$package.foo().
+[4:6..4:9): #*# <- ext/Extension$package.`#*#`().
+[4:11..4:12): i <- ext/Extension$package.`#*#`().(i)
+[4:14..4:17): Int -> scala/Int#
+[4:21..4:27): String -> scala/Predef.String#
+[4:29..4:32): Int -> scala/Int#
+[4:37..4:37): -> scala/Tuple2.apply().
+[4:37..4:38): s -> ext/Extension$package.`#*#`().(s)
+[4:40..4:41): i -> ext/Extension$package.`#*#`().(i)
+[6:4..6:5): a <- ext/Extension$package.a.
+[6:14..6:17): foo -> ext/Extension$package.foo().
+[8:4..8:5): c <- ext/Extension$package.c.
+[8:14..8:17): #*# -> ext/Extension$package.`#*#`().
 
 expect/ForComprehension.scala
 -----------------------------