Modern Fortran

4 Organizing your Fortran code using modules

This chapter covers

• Accessing variables and procedures in modules
• Writing your own custom module
• Refactoring the tsunami simulator with modules

So far, we’ve covered the essential building blocks of Fortran: built-in types and declaration, arithmetic, control flow, and procedures. In theory, this is all you need to write correct and powerful Fortran programs. In practice, however, as your app or library grows in size, organization of your source code becomes ever more important. This is where modules come to the rescue.

Modules allow you to organize variable and procedure definitions in a meaningful way, and make them accessible for use in programs, procedures, or other modules. Modern Fortran ...