Define a primitive data type: Difference between revisions

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 =={{header|E}}==
- def MyNumber := 1..10
+<lang e> def MyNumber := 1..10
  for i :MyNumber in [0, 5, 10, 15, 20, 25] {
      println(i)
- }
+ }</lang>
 (Note: The region guard, while provided with E, is entirely unprivileged code, and could be argued not to be "primitive".)
+=={{header|Fortran}}==
+{{works with|Fortran|90 and later}}
+The module gives an example of how a ''bounded integer'' could be implemented in Fortran (not all the needed interfaces are implemented, and only the one for the + operator are shown). Bounds are checked at run-time.
+<lang fortran>module Bounded
+  implicit none
+  type BoundedInteger
+     integer, private :: v         ! we cannot allow direct access to this, or we
+     integer, private :: from, to  !   can't check the bounds!
+     logical, private :: critical
+  end type BoundedInteger
+  interface assignment(=)
+     module procedure bounded_assign_bb, bounded_assign_bi !, &
+                    ! bounded_assign_ib
+  end interface
+  interface operator(+)
+     module procedure bounded_add_bbb !, bounded_add_bbi, &
+                    ! bounded_add_bib, bounded_add_ibb,   &
+                    ! bounded_add_iib, bounded_add_ibi,   &
+                    ! bounded_add_bii
+  end interface
+  private :: bounded_assign_bb, bounded_assign_bi, &
+             bounded_add_bbb
+contains
+  subroutine set_bound(bi, lower, upper, critical, value)
+    type(BoundedInteger), intent(out) :: bi
+    integer, intent(in) :: lower, upper
+    integer, intent(in), optional :: value
+    logical, intent(in), optional :: critical
+    bi%from = min(lower, upper)
+    bi%to = max(lower, upper)
+    if ( present(critical) ) then
+       bi%critical = critical
+    else
+       bi%critical = .false.
+    end if
+    if ( present(value) ) then
+       bi = value
+    end if
+  end subroutine set_bound
+  subroutine bounded_assign_bb(a, b)
+    type(BoundedInteger), intent(out) :: a
+    type(BoundedInteger), intent(in)  :: b
+    call bounded_assign_bi(a, b%v)
+  end subroutine bounded_assign_bb
+  subroutine bounded_assign_bi(a, b)
+    type(BoundedInteger), intent(out) :: a
+    integer,              intent(in)  :: b
+    if ( (a%from <= b) .and. (a%to >= b) ) then
+       a%v = b
+    else
+       write(0,*) "BoundedInteger: out of bound assignment"
+       if ( a%critical ) then
+          stop
+       else
+          if ( b < a%from ) then
+             a%v = a%from
+          else
+             a%v = a%to
+          end if
+          write(0,"(A,' (',I0, ')')") "BoundedInteger: set to nearest bound", a%v
+       end if
+    end if
+  end subroutine bounded_assign_bi
+  function bounded_add_bbb(a, b) result(c)
+    type(BoundedInteger) :: c
+    type(BoundedInteger), intent(in) :: a, b
+    integer :: t
+    c%from = max(a%from, b%from)
+    c%to   = min(a%to,   b%to)
+    t = a%v + b%v
+    if ( c%from <= t .and. c%to >= t ) then
+       c%v = t
+    else
+       write(0,*) "BoundedInteger: out of bound sum"
+       if ( a%critical .or. b%critical ) then
+          stop
+       else
+          if ( t < c%from ) then
+             c%v = c%from
+          else
+             c%v = c%to
+          end if
+          write(0,"(A,' (',I0,')')") "BoundedInteger: set to nearest bound", c%v
+       end if
+    end if
+  end function bounded_add_bbb
+end module Bounded</lang>
+<lang fortran>program BoundedTest
+  use Bounded
+  implicit none
+  type(BoundedInteger)     ::  a, b, c
+  call set_bound(a, 1, 10)
+  ! if we want to stop the program if a is out of bounds...
+  ! call set_bound(a, 1, 10, critical=.true.)
+  call set_bound(b, 1, 10)
+  call set_bound(c, 1, 10)
+  ! if we want to init c to a specific value...:
+  ! call set_bound(c, 1, 10, value=6)
+  a = 1         ! ok
+  a = 4         ! ok
+  a = -1        ! warning (a=1)
+  a = 11        ! warning (a=10)
+  a = 3         ! ok
+  b = a         ! ok
+  c = a + b     ! ok (3+3)
+  c = c + a     ! ok (6+3=9)
+  c = c + b     ! warning (c=10)
+end program BoundedTest</lang>
 =={{header|Haskell}}==