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! This file is an example to test the syntax highlighting file fortran-free.xml
! (for fortran, free format)
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! THIS IS AN EXAMPLE OF A MODULE !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
<beginfold id='1'>module</beginfold id='1'> module_example
! use 'implicit none' when you want all variables to be declared
implicit none
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! PUBLICS AND PRIVATES
! In fortran 90 you can define your own operator
public :: operator(.norm.)
public :: operator(+) ! <-- you can also overload the usual operators
public :: factorial
public :: example_fn
private :: point3d_add
private :: point3d_norm
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! USER-DEFINED TYPES...
! This is a definition to use in declarations of real variables,
! parameters, etc.
integer, parameter, public :: kr = selected_real_kind(10)
! This is a user-defined type
type, public :: point3d
real(kind=kr) :: x, y, z
end type point3d
! This type is useless: it is only an example of type definition!
type, public :: example_type
complex(kind=kr) :: c ! <-- a complex number (two reals of kind kr)!
real, dimension(-10:10) :: & ! <-- this line does not end here!
r1, r2 ! <-- this is the final part of the previous line
real, pointer, dimension(:) :: pointer_to_array_of_real
real, dimension(:), pointer :: array_of_pointer_to_real
end type example_type
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! INTERFACES...
! Interface for the norm of a 3-D vector
interface operator(.norm.)
module procedure point3d_norm
end interface
! Interface for the operator '+'
interface operator(+)
module procedure point3d_add
end interface
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! SOME DECLARATIONS...
! A real number can be declared with the following line:
real(kind=kr) :: real_var1
! But if you are not interested on the precision of floating point numbers,
! you can use simply:
real :: real_var2
! An array can be declared in two ways:
real(kind=kr), dimension(1:10, -4:5), private :: a, b, c
real(kind=kr), private :: d(1:10, -4:5)
! This is a string with fixed lenght
character(len=10) :: str_var
! This is an allocatable array, which can be a target of a pointer
type(example_type), private, dimension(:), allocatable, target :: &
many_examples
! Fortran 90 hasn't got its own preprocessor, it uses the C preprocessor!
#ifdef XXX
#endif
<endfold id='1'></endfold id='1'><beginfold id='1'>contains</beginfold id='1'>
! The sum of two points
pure <beginfold id='1'>function</beginfold id='1'> point3d_add(a, b) result(rs)
type(point3d) :: rs
type(point3d), intent(in) :: a, b
rs%x = a%x + b%x
rs%y = a%y + b%y
rs%z = a%z + b%z
<endfold id='1'>end function</endfold id='1'> point3d_add
! The norm of a point
pure <beginfold id='1'>function</beginfold id='1'> point3d_norm(a) result(rs)
real(kind=kr) :: rs
type(point3d), intent(in) :: a
rs = sqrt(a%x * a%x + a%y * a%y + a%z * a%z)
<endfold id='1'>end function</endfold id='1'> point3d_norm
! A simple recursive function
recursive <beginfold id='1'>function</beginfold id='1'> factorial(i) result (rs)
integer :: rs
integer, intent(in) :: i
if ( i <= 1 ) <beginfold id='2'>then</beginfold id='2'>
rs = 1
<endfold id='2'></endfold id='2'><beginfold id='2'>else</beginfold id='2'>
rs = i * factorial(i - 1)
<endfold id='2'>end if</endfold id='2'>
<endfold id='1'>end function</endfold id='1'> factorial
! This is a useless function
<beginfold id='1'>subroutine</beginfold id='1'> example_fn(int_arg, real_arg, str_arg)
integer, intent(in) :: int_arg
real(kind=kr), intent(out) :: real_arg
character(len=*), intent(in) :: str_arg
type(example_type), pointer :: p
integer :: n, i, j
logical :: flag
flag = .true. ! .true. is not an operator!
if ( flag .and. flag ) <beginfold id='2'>then</beginfold id='2'> ! .and. is a pre-defined operator
print *, "blabla"
<endfold id='2'>end if</endfold id='2'>
! Examples of inquiry functions: allocated, lbound, ubound.
if ( .not. allocated(many_examples) ) <beginfold id='2'>then</beginfold id='2'>
allocate( many_examples(10) )
<endfold id='2'>end if</endfold id='2'>
print *, "Lower bound = ", lbound(many_examples, 1)
print *, "Upper bound = ", ubound(many_examples, 1)
p => many_examples(5) ! <-- p is a pointer
! A strange way to calculate i*i: add the first i odd numbers
i = 6
j = 0
<beginfold id='2'>do</beginfold id='2'> n = 1, i
j = j + (2*n - 1)
<endfold id='2'>end do</endfold id='2'>
print *, "i*i = ", i*i, j
real_arg = real(j) ! <-- here the highlighting is not very good:
! it is unable to distinguish between this and a definition like:
! real(kind=kr) :: a
deallocate( many_examples )
<endfold id='1'>end subroutine</endfold id='1'> example_fn
<endfold id='1'>end module</endfold id='1'> module_example
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! THIS IS THE MAIN PROGRAM !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
<beginfold id='1'>program</beginfold id='1'> example
use module_example
! this is another example of use of the 'implicit' keyword
implicit double precision (a-h,o-z)
real(kind=kr) :: var_out
type(point3d) :: &
a = point3d(0.0_kr, 1.0_kr, 2.0_kr), &
b = point3d(4.0_kr, 5.0_kr, 6.0_kr)
print *, "a + b = ", .norm. (a + b)
print *, "factorial of 5 = ", factorial(5)
call example_fn(1, var_out, "hello!")
<endfold id='1'>end program</endfold id='1'> example
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