scala3-compiler-bootstrapped/dotty.tools.dotc.typer/VarianceChecker

VarianceChecker

object VarianceChecker

Provides check method to check that all top-level definitions in tree are variance correct. Does not recurse inside methods. The method should be invoked once for each Template.

Companion
class
class Object
trait Matchable
class Any

Type members

Classlikes

case class VarianceError(tvar: Symbol, required: Variance)

Value members

Concrete methods

def check(tree: Tree)(using Context): Unit
def checkLambda(tree: LambdaTypeTree, bounds: TypeBounds)(using Context): Unit

Check that variances of type lambda correspond to their occurrences in its body. Note: this is achieved by a mechanism separate from checking class type parameters. Question: Can the two mechanisms be combined in one?

Check that variances of type lambda correspond to their occurrences in its body. Note: this is achieved by a mechanism separate from checking class type parameters. Question: Can the two mechanisms be combined in one?