Forpedo in Fortran Wiki

**Forpedo** is a preprocessor for [[Fortran 90]] code, written in
Python. It performs some typical preprocessing tasks, such as
including code from one file in another, but it is mostly designed to
assist with advanced techniques in pre-[[Fortran 2003]] versions of the
language. In particular, there is support for C++ like
[[Generic programming|generics]] (templates), and run-time polymorphism from
[[Object-oriented programming]].
The output of Forpedo is standard Fortran code. The output generated
is clean, as if it were written by a programmer, so that if at some
point you stop using Forpedo, you will be left with a high-quality
body of code.
Forpedo was announced on November 24, 2004. Support for run-time
polymorphism was announced on February 16, 2006.
Homepage: <http://www.macanics.net/forpedo/>
## Run-Time Polymorphism
To define a polymorphic type (known as a 'protocol') with Forpedo, you
can do something like this:
~~~~~ {: lang=fortran }
#protocol AnimalProtocol AnimalProtocolMod
#method makeSound
type(AnimalProtocol), intent(in) :: self
#endmethod
#method increaseAgeInAnimalYears increase
type(AnimalProtocol), intent(inout) :: self
integer, intent(in) :: increase
#endmethod
#conformingtype Dog DogMod
#conformingtype Cat CatMod
#endprotocol
~~~~~
To use the type:
~~~~~ {: lang=fortran }
program Main
 use AnimalProtocolMod
 use DogMod
 use CatMod
 type (Dog), target :: d
 type (Cat), target :: c
 type (AnimalProtocol) :: p
 ! Assign protocol to Dog
 p = d
 ! Pass pointer to a subroutine that knows nothing about the concrete type Dog
 call doStuffWithAnimal(p)
 ! Repeat for Cat. Results will be different, though subroutine call is the same.
 p = c
 call doStuffWithAnimal(p)
contains
 subroutine doStuffWithAnimal(a)
 type (AnimalProtocol) :: a
 call makeSound(a)
 call increaseAgeInAnimalYears(a, 2)
 end subroutine
end program
~~~~~
-----
## See Also
* [[Preprocessors]]
* [[Tools]]
## External Links
* [Forpedo homepage](http://www.macanics.net/forpedo/)
* [[ANN] Forpedo: A (python-written) preprocessor for Fortran generics](http://groups.google.com/group/comp.lang.python/browse_thread/thread/e90616957838fff4),
[[comp lang fortran|comp.lang.fortran]],
27 Nov 2004.
* [Forpedo Preprocessor Now Supports Run-Time Polymorhpism](http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/15e547f524f4d58e)
[[comp lang fortran|comp.lang.fortran]],
16 Feb 2006.
## References
* McCormack, D. (2005).
[Generic programming in Fortran with Forpedo](http://doi.acm.org/10.1145/1080399.1080401)
*Fortran Forum*, 24, 18-29.