##-
# Author: Brian Tiffin
# Dedicated to the public domain
#
# Date: November 2016
# Modified: 2016-12-01/00:50-0500
##+
#
# fortran.icn, invoke some gfortran programs and functions
#
# tectonics:
#    gfortran -o fortran-66.so -shared -fpic fortran-66.f
#    gfortran -o fortran-77.so -shared -fpic fortran-77.f
#    gfortran -ffree-form -c -fpic fortran.f
#    gcc -o fortran.so -shared -fpic unifortran.c fortran.o
#
procedure main()
    # load and invoke an old form Fortran main module
    # this could just as well be an open pipe or system call
    # but this is an alpha level proof of mechanism
    fortran66 := loadfunc("./fortran-66.so", "main")
    fortran66()

    # load and invoke another Fortran main module
    # a simple demonstration of variant forms of Fortran source
    fortran77 := loadfunc("./fortran-77.so", "main")
    fortran77()

    # load a Fortran module, and pass arguments
    # any realistic use of Fortran would build on this type of interface
    # or, would require fortran-ization of the C macros in icall.h
    fortran := loadfunc("./fortran.so", "unifortran")
    result := fortran(5)
    write("Subroutine square(5, result) + cube(5) from Fortran: ", result)
end