Issue with printing entries of the dictionary.

[arunprasaad2711]

Hello!
I wrote a small test program to create a dictionary. However, I am not able to print the dictionary or the key values in the dictionary.

This is the sample program

use dictionary implicit none type(dict) :: sample_dict1 integer :: nx = 101, ny = 201, nt = 10001 sample_dict1 = ('nx'.kv.nx) // ('ny'.kv.ny) // ('nt'.kv.nt) print *, sample_dict1

[zerothi]

You cannot print a derived type in fortran. There is no possible overloading of a write statement.

However, you can print a dictionary:

type(dict) :: d
call print(d)

[zbeekman]

@zerothi

You cannot print a derived type in fortran. There is no possible overloading of a write statement.

I don't think that's strictly correct with Modern Fortran. What about derived type IO? See Modern Fortran Explained, Section "17.2 Non-default derived-type input/output"

You can have TBPs overloading IO for derived types:

generic :: read(formatted) => r1, r2
generic :: read(unformatted) => r3, r4, r5
generic :: write(formatted) => w1
generic :: write(unformatted) => w2, w3

e.g.:

program
  use person_module
  integer id, members
  type (person) :: chairman
  :
  write (6, fmt="(i2, dt(15,6), i5)" ) id, chairman, members
  ! This writes a record with four fields, with lengths 2, 15, 6, 5,
  ! respectively
end program

module person_module
  type :: person
    character (len=20) :: name
    integer :: age
  contains
    procedure :: pwf
    generic :: write(formatted) => pwf
  end type person
contains
  subroutine pwf (dtv, unit, iotype, vlist, iostat, iomsg)
    ! Arguments
    class(person), intent(in) :: dtv
    integer, intent(in) :: unit
    character (len=*), intent(in) :: iotype
    integer, intent(in) :: vlist(:)
    ! vlist(1) and (2) are to be used as the field widths
    ! of the two components of the derived type variable.
    integer, intent(out) :: iostat
    character (len=*), intent(inout) :: iomsg
    ! Local variable
    character (len=9) :: pfmt
    ! Set up the format to be used for output
    write (pfmt, ’(a,i2,a,i2,a)’ ) &
      ’(a’, vlist(1), ’,i’, vlist(2), ’)’
    ! Now the child output statement
    write (unit, fmt=pfmt, iostat=iostat) dtv%name, dtv%age
  end subroutine pwf
end module person_module

[zerothi]

Yes, but in modern fortran fdict has less importance (everything can be handled with classes). It is primarily a f90 module and in f90 (f95) this is not possible.

Thanks for the elaborate example though. :)