Encode variances in parameter names

This leads to a slight overall simplification, harmonizes pickle
format with internal representation, and makes MethodTypes and
PolyTypes more similar to each other.

I believe the change is useful as it is, but in particular it is
a useful step for an eventual unification of MethodTypes and
PolyTypes.

1 files changed, 1 insertions, 5 deletions

diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala b/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala
index cb1b56c3c..98577f3c5 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala
@@ -151,7 +151,7 @@ Standard-Section: "ASTs" TopLevelStat*
                   BIND           Length boundName_NameRef bounds_Type
                                         // for type-variables defined in a type pattern
                   BYNAMEtype            underlying_Type
-                  POLYtype       Length result_Type NamesTypes      // variance encoded in front of name: +/-/=
+                  POLYtype       Length result_Type NamesTypes      // variance encoded in front of name: +/-/(nothing)
                   METHODtype     Length result_Type NamesTypes      // needed for refinements
                   PARAMtype      Length binder_ASTref paramNum_Nat  // needed for refinements
                   SHARED                type_ASTRef
@@ -546,8 +546,4 @@ object TastyFormat {
     case POLYtype | METHODtype => -1
     case _ => 0
   }
-
-  /** Map between variances and name prefixes */
-  val varianceToPrefix = Map(-1 -> '-', 0 -> '=', 1 -> '+')
-  val prefixToVariance = Map('-' -> -1, '=' -> 0, '+' -> 1)
 }