tests/ctags/pure_elem.f95

   1 !       elemental
   2 !
   3 !Pure procedures are procedures declared with the PURE keyword and which
   4 !satisfy certain constraints that ensure they have no side
   5 !effects. They can be used in specification expressions and
   6 !within FORALL constructs and statements.
   7
   8 !Elemental procedures can be written in Fortran 95 using the ELEMENTAL
   9 !keyword. Elemental procedures are automatically ``pure''.
  10
  11 !Example:
  12
  13         PURE REAL FUNCTION pure_func(x,y) ! pure okay
  14                 IMPLICIT NONE
  15                 REAL, INTENT(IN) ::  x, y
  16                 pure_func = x*x + y*y + 2*x*y + ASIN(MIN(x/y,y/x))
  17         END FUNCTION pure_func
  18
  19         PURE REAL FUNCTION F(x,y) ! pure broken returns 'PURE REAL FU'
  20                 IMPLICIT NONE
  21                 REAL, INTENT(IN) ::  x, y
  22                 F = x*x + y*y + 2*x*y + ASIN(MIN(x/y,y/x))
  23         END FUNCTION F
  24
  25
  26         ELEMENTAL REAL FUNCTION elem_maxabs(a,b) ! elemental broke
  27                 IMPLICIT NONE
  28                 REAL,INTENT(IN) :: a,b
  29                 elem_maxabs = MAX(ABS(a),ABS(b))
  30         END
  31
  32         PURE REAL FUNCTION pure_maxabs2(a,b) ! pure okay
  33                 IMPLICIT NONE
  34                 REAL,INTENT(IN) :: a,b
  35                 pure_maxabs2 = MAX(ABS(a),ABS(b))
  36         END
  37