Complete the Fortran interface and extend the Python interface

examples/.gitignore

@@ -1,2 +1,9 @@
 *.pineappl
 *.pineappl.lz4
+
+fortran/dyaa
+fortran/test
+fortran/lhapdf_example
+
+**/*.o
+**/*.mod

examples/fortran/Makefile

@@ -1,6 +1,17 @@
 FC = gfortran
-FFLAGS = -Wall -Wextra -O3
+FFLAGS = -Wall -Wextra -O0 -g
 PINEAPPL_LIBS != pkg-config pineappl_capi --libs
+LHAPDF_LIBS != pkg-config lhapdf --libs
 
-all: pineappl.f90 dyaa.f90
-	$(FC) $(FFLAGS) pineappl.f90 dyaa.f90 $(PINEAPPL_LIBS) -o dyaa
+%.o: %.f90
+	$(FC) $(FFLAGS) -c $<
+
+all: pineappl.o dyaa.o test.o
+	$(FC) $(FFLAGS) dyaa.o pineappl.o $(PINEAPPL_LIBS) -o dyaa
+	$(FC) $(FFLAGS) test.o pineappl.o $(PINEAPPL_LIBS) -o test
+
+lhapdf_example: pineappl.o lhapdf_example.o
+	$(FC) $(FFLAGS) lhapdf_example.o pineappl.o $(LHAPDF_LIBS) $(PINEAPPL_LIBS) -o lhapdf_example
+
+clean:
+	rm -f *.o *.mod dyaa test lhapdf_example

examples/fortran/lhapdf_example.f90

@@ -0,0 +1,105 @@
+program lhapdf_example
+    use iso_c_binding
+    use pineappl
+
+    implicit none
+
+    integer, parameter :: dp = kind(0.0d0)
+
+    type(pineappl_grid) :: grid
+    type(pineappl_lumi) :: lumi
+    type(pineappl_keyval) :: key_vals
+
+    procedure (pineappl_xfx), pointer :: xfx
+    procedure (pineappl_alphas), pointer :: alphas
+
+    integer, target :: flags(2)
+
+    lumi = pineappl_lumi_new()
+    call pineappl_lumi_add(lumi, 2, [0, 0, 1, -1, 2, -2], [1.0_dp, 1.0_dp, 1.0_dp])
+
+    key_vals = pineappl_keyval_new()
+    grid = pineappl_grid_new(lumi, 1, [2, 0, 0, 0], 2, [0.0_dp, 1.0_dp, 2.0_dp], key_vals)
+
+    call pineappl_grid_fill_all(grid, 0.5_dp, 0.5_dp, 100.0_dp, 0, 0.5_dp, [0.5_dp, 0.5_dp, 0.5_dp])
+    call pineappl_grid_fill_all(grid, 0.5_dp, 0.5_dp, 100.0_dp, 0, 1.5_dp, [1.5_dp, 1.5_dp, 1.5_dp])
+
+    call lhapdf_initpdfset_byname(0, "nCTEQ15_1_1")
+    call lhapdf_initpdfset_byname(1, "nCTEQ15FullNuc_208_82")
+
+    ! calling pineappl_grid_convolute without any flags
+    xfx => xfx_test1
+    alphas => alphas_test1
+    write(*, *) "first pineappl_grid_convolute_with_one: "
+    write(*, *) pineappl_grid_convolute_with_one(grid, 2212, xfx, alphas, &
+        [.true., .true.], [.true., .true.], 1.0_dp, 1.0_dp)
+
+    ! calling pineappl_grid_convolute with two integer flags that are used in xfx_test2 and alphas_test2 to determine the set and member indices
+    xfx => xfx_test2
+    alphas => alphas_test2
+    flags = [1, 0]
+    write(*, *) "second pineappl_grid_convolute_with_one: "
+    write(*, *) pineappl_grid_convolute_with_one(grid, 2212, xfx, alphas, &
+        [.true., .true.], [.true., .true.], 1.0_dp, 1.0_dp, c_loc(flags(1)))
+contains
+
+    ! Passing a Fortran procedure to C needs the iso_c_binding
+    function xfx_test1(pdg_id, x, q2, state) bind(c)
+        use iso_c_binding
+
+        implicit none
+
+        integer(c_int32_t), value, intent(in) :: pdg_id
+        real(c_double), value, intent(in)     :: x, q2
+        type(c_ptr), value, intent(in)        :: state
+        real(c_double)                        :: xfx_test1
+
+        call lhapdf_xfxq2(0, 0, pdg_id, x, q2, xfx_test1)
+    end function
+
+    function xfx_test2(pdg_id, x, q2, state) bind(c)
+        use iso_c_binding
+
+        implicit none
+
+        integer(c_int32_t), value, intent(in) :: pdg_id
+        real(c_double), value, intent(in)     :: x, q2
+        type(c_ptr), value, intent(in)        :: state
+        real(c_double)                        :: xfx_test2
+
+        integer, pointer :: flags(:)
+
+        call c_f_pointer(state, flags, [2])
+
+        call lhapdf_xfxq2(flags(1), flags(2), pdg_id, x, q2, xfx_test2)
+    end function
+
+    function alphas_test1(q2, state) bind(c)
+        use iso_c_binding
+
+        implicit none
+
+        real(c_double), value, intent(in) :: q2
+        type(c_ptr), value, intent(in)    :: state
+        real(c_double)                    :: alphas_test1
+
+        call lhapdf_alphasq2(0, 0, q2, alphas_test1)
+    end function
+
+    function alphas_test2(q2, state) bind(c)
+        use iso_c_binding
+
+        implicit none
+
+        real(c_double), value, intent(in) :: q2
+        type(c_ptr), value, intent(in)    :: state
+        real(c_double)                    :: alphas_test2
+
+        integer, pointer :: flags(:)
+
+        call c_f_pointer(state, flags, [2])
+
+        call lhapdf_alphasq2(0, 0, q2, alphas_test2)
+    end function
+
+end program lhapdf_example