The functions toType, toTypes, and fromType convert Curry type expressions into types and vice versa. The functions qualifyType and unqualifyType add and remove module qualifiers in a type, respectively.

When Curry type expression are converted with toType or toTypes, type variables are assigned ascending indices in the order of their occurrence. It is possible to pass a list of additional type variables to both functions which are assigned indices before those variables occurring in the type. This allows preserving the order of type variables in the left hand side of a type declaration.