scaladoc: skip parens around occurences of the same operator

Author: Florian3k

scaladoc-testcases/src/tests/infixTypes.scala

@@ -19,8 +19,12 @@ def someTrait3[G, H]: G SomeTrait2 H //expected: def someTrait3[G, H]: SomeTrait
 
 trait +++[A, B]
 
+trait ++*[A, B]
+
 trait ++:[A, B]
 
+trait +*:[A, B]
+
 trait ***[A, B]
 
 trait **:[A, B]
@@ -30,26 +34,44 @@ def foo[A, B, C, D]: (A SomeTrait B) +++ (C SomeTrait2 D) //expected: def foo[A,
 
 // left-associative, same precedence
 
-def a0[X, Y, Z]: X +++ Y +++ Z //expected: def a0[X, Y, Z]: (X +++ Y) +++ Z
+def a0[X, Y, Z]: X +++ Y +++ Z
   = a1
 
-def a1[X, Y, Z]: (X +++ Y) +++ Z
+def a1[X, Y, Z]: (X +++ Y) +++ Z //expected: def a1[X, Y, Z]: X +++ Y +++ Z
   = a0
 
 def a2[X, Y, Z]: X +++ (Y +++ Z)
   = ???
 
-// right-associative, same precedence
+def a0x[X, Y, Z]: X +++ Y ++* Z //expected: def a0x[X, Y, Z]: (X +++ Y) ++* Z
+  = a1x
 
-def a3[X, Y, Z]: X ++: Y ++: Z //expected: def a3[X, Y, Z]: X ++: (Y ++: Z)
+def a1x[X, Y, Z]: (X +++ Y) ++* Z
+  = a0x
+
+def a2x[X, Y, Z]: X +++ (Y ++* Z)
   = ???
 
+// right-associative, same precedence
+
+def a3[X, Y, Z]: X ++: Y ++: Z
+  = a5
+
 def a4[X, Y, Z]: (X ++: Y) ++: Z
   = ???
 
-def a5[X, Y, Z]: X ++: (Y ++: Z)
+def a5[X, Y, Z]: X ++: (Y ++: Z) //expected: def a5[X, Y, Z]: X ++: Y ++: Z
+  = a3
+
+def a3x[X, Y, Z]: X ++: Y +*: Z  //expected: def a3x[X, Y, Z]: X ++: (Y +*: Z)
+  = a5x
+
+def a4x[X, Y, Z]: (X ++: Y) +*: Z
   = ???
 
+def a5x[X, Y, Z]: X ++: (Y +*: Z)
+  = a3x
+
 // left and right associative, same precedence
 
 def a6[X, Y, Z]: (X +++ Y) ++: Z

scaladoc/src/dotty/tools/scaladoc/tasty/TypesSupport.scala

@@ -365,7 +365,11 @@ trait TypesSupport:
       case (at: AppliedType, _: OrType)  => at.isFunctionType || isInfix(at)
       case (_: AndType, at: AppliedType) => isInfix(at)
       case (_: OrType, at: AppliedType)  => isInfix(at)
-      case (at1: AppliedType, at2: AppliedType) => isInfix(at2) && (at1.isFunctionType || isInfix(at1))
+      case (at1: AppliedType, at2: AppliedType) =>
+        val leftAssoc = !at1.tycon.typeSymbol.name.endsWith(":")
+        isInfix(at2) && (at1.isFunctionType || isInfix(at1) && (
+          at1.tycon.typeSymbol != at2.tycon.typeSymbol || leftAssoc != isLeft
+        ))
       case _ => false
 
   private def isInfix(using Quotes)(at: reflect.AppliedType) =