General organization

As input, Mosel expects a text file containing the source of the model/program to execute (henceforth we use just the term 'model' for 'model/program' except where there might be an ambiguity). This source file is first compiled by the Mosel compiler. During this operation, the syntax of the model is checked but no operation is executed. The result of the compilation is a BInary Model (BIM) that is saved in a second file. In this form, the model is ready to be executed and the source file is not required any more. To actually 'run' the model, the BIM file must be read in again by Mosel and then executed. These different phases are handled by different modules that comprise the Mosel environment:

The runtime library: This library contains the VIrtual MAchine (VIMA) interpreter. It knows how to load a model in its binary format and how to execute it. It also implements a model manager (for handling several models at a time) and a Dynamic Shared Objects manager (for loading and unloading modules required by a given model). All the features of this library can be accessed from a user application.

The compiler library: The role of this module is to translate a source file into a binary format suitable for being executed by the VIMA Interpreter.

The standalone application: The 'mosel' application, also known as 'Mosel Console', is a command line interpreter linked to the two previous modules. It provides a single program to compile and execute models.

Various modules: These modules complete the Mosel set of functionalities by providing, for instance, optimization procedures. As an example, the mmxprs module extends the Mosel language with the procedure maximize that optimizes the current problem using the Xpress Optimizer.

This modularized structure offers various advantages:

• Once compiled, a model can be run several times, for instance with different data sets, without the need for recompiling it.
• The compiled form of the program is system and architecture independent: it can be run on any operating system equipped with the Mosel runtime library and any modules required.
• The BIM file can be generated in order to contain no symbols at all. It is then safe, in terms of intellectual property, to distribute a model in its binary form.
• As a library, Mosel can be easily integrated into a larger application. The model may be provided as a BIM file and the application only linked to the runtime library.
• The Mosel system does not integrate any kind of solver but is designed in a way that a module can provide solving facilities. The direct consequence of this is that Mosel can be linked to different solvers and communicate with them directly through memory.
• This open architecture of Mosel makes extensions of the functionality possible on a case by case basis, without the need to modify the Mosel internals.