Creating external types

Mosel modules may create new types (referred to as external as opposed to the default types that are internal to Mosel), for instance other types of variables to be handled by specific solution algorithms, structures regrouping data items, or additional types of numbers. To be able to work with a new type in a Mosel program, it is not sufficient simply to define this type in a module. The module must also define all actions that one wants to be able to apply to objects of this type: creation, initialization, assignment, deletion, arithmetic operations and comparisons are typical examples. Once a new type has been created, it is treated just like a genuine type of Mosel, e.g. it becomes possible to define arrays and sets of this type or to use it as a function parameter.