Styleguide

General

• Line-endings: all line-endings should be Windows line-endings (CR-LF), git needs to be set to not change this: git config --global core.autocrlf true
• Encoding: for historical reasons, all source files should be encoded in ISO-8859-1

Fortran

Visual Studio 2005 Fortran tabstop settings

• Indenting: three-character indents, tabs saved as spaces
• Keywords (e.g. IF, FUNCTION, INTEGER etc.) should be capitalized.
• The keywords END IF, END DO etc. should be written with a space as shown here.

Operators

The modern form of operator syntax should be preferred (e.g. >= rather than .GE.). A lot of code currently still uses the old format, though.

Description	Old syntax	New syntax
Less than	.LT.	<
Less than or equal to	.LE.	<=
Equal to	.EQ.	==
Not equal to	.NE.	/=
Greater than	.GT.	>
Greater than or equal to	.GE.	>=

General formatting

NOTE: There is still some debate about how code should be formatted. We might look into using an autoformatter such as fprettify in the future.

Funktionen sollten folgendermaßen formatiert werden:

• Vorschlag A

CXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
c     Funktionsbeschreibung
      FUNCTION FOO (BAR) RESULT (LOK)
c     .................................................................
      USE MODULE
      INTEGER  i
      LOGICAL  LOK
      character(*) str
c     .................................................................
      LOK = .FALSE.

c     Kommentar
      DO i = 1, 10
         CALL FOOBAR()
         IF (.NOT. LOK) GOTO 9999
      END DO
      LOK = .TRUE.
      GOTO 10000
c     .................................................................
c     Fehlerbehandlung
9999  IF (.NOT. LOK) ERROR = FEHLER(50, '    ', '    ', 0)
      GOTO 10000
c     .................................................................
10000 RETURN
      END FUNCTION FOO
cxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

• Vorschlag B

C----------------------------------------------------------------------
C MOD_Beispiel: Ein Modul !
c Anmerkung: blabla
C----------------------------------------------------------------------
      module MOD_Beispiel
      use MODULE_BLABLAblabla
      implicit none
      
      integer MemberInt

      contains      

C----------------------------------------------------------------------
C funktion FOO : Eine unsinnige zu Demonstrationszwecken erstellte virtuelle Fkt
c Anmerkung: gibt false zurück wenn Fehler !
C----------------------------------------------------------------------
      logical function FOO (BAR)
      use MODULE_BLABLA

         integer  i
         logical  LOK
         character(*) str
      
         FOO = .FALSE.

         !---------------------------------------------
         !Abschnitt A
         !---------------------------------------------
         do i = 1, 10
            CALL FOOBAR()
            !Wenn fehler dann raus !
            IF (.NOT. LOK)
               ERROR = FEHLER(50, '    ', '    ', 0)
               return
            end if
         end do

         FOO = .TRUE.
         return
      end function FOO

      end module MOD_Beispiel