Align Permissions example with its test file

Author: dwijnand

tests/pos/reference/opaque.scala

@@ -1,77 +1,84 @@
-object Logarithms {
+object MyMath:
 
   opaque type Logarithm = Double
 
-  object Logarithm {
+  object Logarithm:
+
+    // These are the two ways to lift to the Logarithm type
 
-    // These are the ways to lift to the logarithm type
     def apply(d: Double): Logarithm = math.log(d)
 
     def safe(d: Double): Option[Logarithm] =
-      if (d > 0.0) Some(math.log(d)) else None
-  }
+      if d > 0.0 then Some(math.log(d)) else None
+
+  end Logarithm
 
   // Extension methods define opaque types' public APIs
   extension (x: Logarithm)
     def toDouble: Double = math.exp(x)
     def + (y: Logarithm): Logarithm = Logarithm(math.exp(x) + math.exp(y))
     def * (y: Logarithm): Logarithm = x + y
-}
 
-object LogTest {
-  import Logarithms.*
+end MyMath
+
+object LogTest:
+  import MyMath.Logarithm
   import Predef.{any2stringadd as _, *}
 
   val l = Logarithm(1.0)
   val l2 = Logarithm(2.0)
   val l3 = l * l2
   val l4 = l + l2
-}
 
 
-object Access {
+
+object Access:
 
   opaque type Permissions = Int
   opaque type PermissionChoice = Int
   opaque type Permission <: Permissions & PermissionChoice = Int
 
-  extension (x: Permissions)
-    def & (y: Permissions): Permissions = x | y
   extension (x: PermissionChoice)
     def | (y: PermissionChoice): PermissionChoice = x | y
+  extension (x: Permissions)
+    def & (y: Permissions): Permissions = x | y
   extension (granted: Permissions)
     def is(required: Permissions) = (granted & required) == required
-  extension (granted: Permissions)
     def isOneOf(required: PermissionChoice) = (granted & required) != 0
 
   val NoPermission: Permission = 0
   val Read: Permission = 1
   val Write: Permission = 2
   val ReadWrite: Permissions = Read | Write
   val ReadOrWrite: PermissionChoice = Read | Write
-}
 
-object User {
+end Access
+
+object User:
   import Access.*
 
   case class Item(rights: Permissions)
+  extension (item: Item)
+    def +(other: Item): Item = Item(item.rights & other.rights)
 
   val roItem = Item(Read)  // OK, since Permission <: Permissions
+  val woItem = Item(Write)
   val rwItem = Item(ReadWrite)
   val noItem = Item(NoPermission)
 
-  assert( roItem.rights.is(ReadWrite) == false )
-  assert( roItem.rights.isOneOf(ReadOrWrite) == true )
+  assert(!roItem.rights.is(ReadWrite))
+  assert(roItem.rights.isOneOf(ReadOrWrite))
 
-  assert( rwItem.rights.is(ReadWrite) == true )
-  assert( rwItem.rights.isOneOf(ReadOrWrite) == true )
+  assert(rwItem.rights.is(ReadWrite))
+  assert(rwItem.rights.isOneOf(ReadOrWrite))
 
-  assert( noItem.rights.is(ReadWrite) == false )
-  assert( noItem.rights.isOneOf(ReadOrWrite) == false )
+  assert(!noItem.rights.is(ReadWrite))
+  assert(!noItem.rights.isOneOf(ReadOrWrite))
 
+  assert((roItem + woItem).rights.is(ReadWrite))
   // Would be a type error:
-  //   assert( roItem.rights.isOneOf(ReadWrite) == true )
-}
+  //   assert(roItem.rights.isOneOf(ReadWrite))
+end User
 
 object o {
   opaque type T = Int