Calling Fortran from Gambit-C

Makefile

gambit:
	gfortran -c sum_to_n.f90 -o sum_to_n.o
	gsc -ld-options sum_to_n.o sum_to_n.scm

clean:
	rm sum_to_n.o*

sum_to_n.f90

integer function sum_to_n(n) result(sum) bind(C, name="sum_to_n")
  use iso_c_binding
  implicit none

  integer, intent(in) :: n
  integer :: i, s
  s = 0
  do i = 1, n
     s = s + i
  end do
  sum = s
end function sum_to_n

sum_to_n.scm

(c-declare "int sum_to_n(int *n);")

(define sum-to-n (c-lambda (int) int "___return(sum_to_n(&___arg1));"))