diff options
| -rw-r--r-- | src/dotty/tools/dotc/core/Constraint.scala | 9 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 7 |
2 files changed, 14 insertions, 2 deletions
diff --git a/src/dotty/tools/dotc/core/Constraint.scala b/src/dotty/tools/dotc/core/Constraint.scala index 8704a35d8..b47cc921c 100644 --- a/src/dotty/tools/dotc/core/Constraint.scala +++ b/src/dotty/tools/dotc/core/Constraint.scala @@ -59,6 +59,15 @@ class Constraint(val myMap: SimpleMap[PolyType, Array[Type]]) extends AnyVal wit */ def bounds(param: PolyParam): TypeBounds = at(param).asInstanceOf[TypeBounds] + /** The type variable corresponding to parameter `param`, or + * NoType, if `param` is not in constrained or is not paired with a type variable. + */ + def typeVarOfParam(param: PolyParam): Type = { + val entries = myMap(param.binder) + if (entries == null) NoType + else typeVar(entries, param.paramNum) + } + /** A new constraint which is derived from this constraint by adding or replacing * the entries corresponding to `pt` with `entries`. */ diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 4b3dfe2b7..85e89fa62 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -857,7 +857,8 @@ object Types { * variable instances and reduces typerefs over refined types. It also * re-evaluatesall occurrences of And/OrType with &/| because * what was a union or intersection of type variables might be a simpler type - * after the type variables are instantiated. + * after the type variables are instantiated. Finally, it + * maps poly params in the current constraint set back to their type vars. */ def simplified(implicit ctx: Context) = { class Simplify extends TypeMap { @@ -866,6 +867,8 @@ object Types { mapOver(l) & mapOver(r) case OrType(l, r) => mapOver(l) | mapOver(r) + case tp: PolyParam => + ctx.typerState.constraint.typeVarOfParam(tp) orElse tp case _ => mapOver(tp) } @@ -1736,7 +1739,7 @@ object Types { def isInstantiated(implicit ctx: Context) = instanceOpt.exists /** Instantiate variable with given type */ - def instantiateWith(tp: Type)(implicit ctx: Context): Type = { + private def instantiateWith(tp: Type)(implicit ctx: Context): Type = { assert(tp ne this) typr.println(s"instantiating ${this.show} with ${tp.show}") assert(ctx.typerState.constraint contains this) // !!! DEBUG |