Selective caching of SelectionProtos and ViewProtos

We cache SelectionProtos if their "compat" parameter is "NoViewsAllowed". We always cache ViewProtos.

That's important for implicit search, because this enables eligible refs to be better cached. To make this work, we add a case to WildApprox which massages SelectionProtos so they also get noViewsAllowed in the compat parameter.

1 files changed, 5 insertions, 38 deletions

diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala
index 4f740d2e5..63c26a6e7 100644
--- a/src/dotty/tools/dotc/core/Types.scala
+++ b/src/dotty/tools/dotc/core/Types.scala
@@ -961,8 +961,8 @@ object Types {
   /** A trait for proto-types, used as expected types in typer */
   trait ProtoType extends Type {
     def isMatchedBy(tp: Type)(implicit ctx: Context): Boolean
-    def fold[T](x: T, ta: TypeAccumulator[T]): T
-    def map(tm: TypeMap): ProtoType
+    def fold[T](x: T, ta: TypeAccumulator[T])(implicit ctx: Context): T
+    def map(tm: TypeMap)(implicit ctx: Context): ProtoType
   }
 
   /** Implementations of this trait cache the resukts of `narrow`. */
@@ -1491,7 +1491,7 @@ object Types {
     extends MethodType(paramNames, paramTypes)(resultTypeExp) {
     override def isJava = true
     override def equals(that: Any) = super.equals(that) && that.isInstanceOf[JavaMethodType]
-    override def computeHash = super.computeHash + 1
+    override def computeHash = addDelta(super.computeHash, 1)
     override protected def prefixString = "JavaMethodType"
   }
 
@@ -1499,7 +1499,7 @@ object Types {
     extends MethodType(paramNames, paramTypes)(resultTypeExp) {
     override def isImplicit = true
     override def equals(that: Any) = super.equals(that) && that.isInstanceOf[ImplicitMethodType]
-    override def computeHash = super.computeHash + 2
+    override def computeHash = addDelta(super.computeHash, 2)
     override protected def prefixString = "ImplicitMethodType"
   }
 
@@ -1612,7 +1612,7 @@ object Types {
     def copyBoundType(bt: BT) = MethodParam(bt, paramNum)
 
     // need to customize hashCode and equals to prevent infinite recursion for dep meth types.
-    override def computeHash = avoidNotCached(System.identityHashCode(binder) + paramNum)
+    override def computeHash = addDelta(System.identityHashCode(binder), paramNum)
     override def equals(that: Any) = that match {
       case that: MethodParam =>
         (this.binder eq that.binder) && this.paramNum == that.paramNum
@@ -2173,39 +2173,6 @@ object Types {
     def apply(tp: Type) = tp
   }
 
-  /** Approximate occurrences of parameter types and uninstantiated typevars
-   *  by wildcard types.
-   */
-  class WildApprox(implicit ctx: Context) extends TypeMap {
-    override def apply(tp: Type) = tp match {
-      case PolyParam(pt, pnum) =>
-        WildcardType(apply(pt.paramBounds(pnum)).bounds)
-      case MethodParam(mt, pnum) =>
-        WildcardType(TypeBounds.upper(apply(mt.paramTypes(pnum))))
-      case tp: TypeVar =>
-        val inst = tp.instanceOpt
-        apply(inst orElse WildcardType(ctx.typerState.constraint.bounds(tp.origin)))
-      case tp: AndType =>
-        val tp1a = apply(tp.tp1)
-        val tp2a = apply(tp.tp2)
-        def wildBounds(tp: Type) =
-          if (tp.isInstanceOf[WildcardType]) tp.bounds else TypeBounds.upper(tp)
-        if (tp1a.isInstanceOf[WildcardType] || tp2a.isInstanceOf[WildcardType])
-          WildcardType(wildBounds(tp1a) & wildBounds(tp2a))
-        else
-          tp.derivedAndType(tp1a, tp2a)
-      case tp: OrType =>
-        val tp1a = apply(tp.tp1)
-        val tp2a = apply(tp.tp2)
-        if (tp1a.isInstanceOf[WildcardType] || tp2a.isInstanceOf[WildcardType])
-          WildcardType(tp1a.bounds | tp2a.bounds)
-        else
-          tp.derivedOrType(tp1a, tp2a)
-      case _ =>
-        mapOver(tp)
-    }
-  }
-
   // ----- TypeAccumulators ----------------------------------------------------
 
   abstract class TypeAccumulator[T](implicit ctx: Context) extends ((T, Type) => T) {