inexhaustiveError is returned from check for each occurrence of inexhaustive case analysis in a Go type switch statement.

notFoundError corresponds to a declared sum type whose type definition could not be found in the same Go package.

notInterfaceError corresponds to a declared sum type that does not correspond to an interface.

sumTypeDecl is a declaration of a sum type in a Go source file.

sumTypeDef corresponds to the definition of a Go interface that is interpreted as a sum type. Its variants are determined by finding all types that im

unsealedError corresponds to a declared sum type whose interface is not sealed. A sealed interface requires at least one unexported method.