TypeApplications

Extractor for

[X1: B1, ..., Xn: Bn] -> C[X1, ..., Xn]

where B1, ..., Bn are bounds of the type parameters of the class C.

A type map that tries to reduce (part of) the result type of the type lambda tycon with the given args(some of which are wildcard arguments represented by type bounds). Non-wildcard arguments are substituted everywhere as usual. A wildcard argument `>: L : L : L <: H

Any other occurrence of X in tycon is replaced by U, if the occurrence of X in tycon is covariant, or nonvariant, or by L, if the occurrence is contravariant.

The idea is that the AllowLambdaWildcardApply mode is used to check whether a type can be soundly reduced, and to give an error or warning if that is not the case. By contrast, the default mode, with AllowLambdaWildcardApply not set, reduces all applications even if this yields a different type, so its postcondition is that no type parameters of tycon appear in the result type. Using this mode, we can guarantee that appliedTo will never produce a higher-kinded application with a type lambda as type constructor.

Adapt all arguments to possible higher-kinded type parameters using etaExpandIfHK

Assert type is not a TypeBounds instance and return it unchanged