Data values which have to be exchanged between various algorithms are represented by Parameter classes. These are specializations of the Algorithm Library template class Parameter with user defined C++ classes representing the actual data value. Parameter classes comprehend the MDL-name, an MdlString containing optional documentation, MDL-type information and pointers to the value and the optional default value of the Parameter.
The Parameter class is derived from the virtual base class AnyParameter defining the polymorphic method interface of the Parameter template. References to the AnyParameter parents and their methods are the only access points of the Algorithm Library to instances of the various Parameter class types.