Re: Proper way to return a string

In article <1167448598.037577.155500@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"Beliavsky" <beliavsky@xxxxxxx> wrote:

I don't think a function have a character(len=*) RESULT . For example,
for the following code

module string_func_mod
implicit none
contains
subroutine str_sub(aa,bb)
character (len=*), intent(in) :: aa
character (len=*), intent(out) :: bb
bb = aa
end subroutine str_sub
!
function str_func(aa) result(bb)
character (len=*), intent(in) :: aa
character (len=*) :: bb
bb = aa
end function str_func
end module string_func_mod

g95 says

In file string_func.f90:10

function str_func(aa) result(bb)
1
Error: Internal function 'str_func' at (1) cannot be an assumed-length
CHARACTER

The following code is legal f90, and without the result(), it would
be legal f77:

function str_func(aa) result(bb)
character (len=*) :: bb
character (len=*), intent(in) :: aa
bb = aa
end function str_func

I don't know why your original code does not compile. I expect that
it is some subtle difference between module functions (which are f90
only) and external functions (which are common to both f77 and f90).

For a subroutine argument, the LEN of the character argument is the
same on output as on input, but for a function, the compiler would not
"know" what the LEN of a character (len=*) RESULT is.

The compiler "knows" the length of the function result the same way
it "knows" the length of the argument. Namely, it is determined by
the calling routine.

$.02 -Ron Shepard
.

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