An example application of Scheme calling into Ada, and Ada calling back to Scheme.
For the time being, it only supports GPRBuild (Ada) and Chicken Scheme. The quickest way to build it is to have both tools installed and run:
make
That will create an executable in the root folder called scheme_ada. Run it and see what you get.
The more manual approach would be to execute the gprbuild (Ada build tool) and csc (Chicken compiler) separately in the root folder.
gprbuild -Pscheme.gpr
csc chicken_ada.scm -L./lib -L -lscheme_hello -Wl,-R./lib -v -o scheme_ada
For the time being, the GNATTools toolsuite is not working. I am having tremendous issues with the linking step. Everything else seems to function. The Makefile is of horrible quality, but it has automatic detection of gprbuild. If it is not present in the system, it tries to use GNATTools.
We have a piece of Ada code (the .ads, .adb files in ./src) that is built as a dynamic library, which is placed under ./lib. Then we have a small Scheme file chicken_ada.scm in the root of the project.
The Ada code contains a procedure called hello_ada which is exported as a C function. In Scheme, we write the prototype of that function so that it can be called. At the same time, in Scheme we create a Scheme function, hello_scheme that will be exported as a C function. During the execution of hello_ada, we call hello_scheme to fully prove the interoperability.
I would like to thank the #chicken community for dealing with my questions and mistakes. Specially jjhoo.
I would also like to thank the #ada community and specially onox, who found the missing link.