Free Form Calcs

One of the major new features of RPG 4, introduced in V5R1, is free form calculation specifications.

Features

• Removes the column restrictions on calculations.
• Can be interspersed with standard, fixed form, calcs

Usage

Using free form calculations is quite easy.

• To start a section of free form calculations, simply put '/free' starting in column 7.
• On the next line start your free form calculations.
• Each line must end with a semi-colon ";".
• Calculations can span multiple lines.
• End the free form calculation area by putting '/end-free' starting in column 7 on the last line.

Limitations

certain opcodes have not been implemented in free form RPG. Many have been replaced with corresponding built in functions.

These include ...

• Move operations (it is debatable as to the wisdom of not supporting these operations)
  • MOVE
  • MOVEL
  • MOVEA
  • MHHZO
  • MHLZO
  • MLHZO
  • MLLZO
• Arithmetic operations (use free form evaluations or corresponding built in function)
  • ADD
  • SUB
  • DIV
  • MULT
  • MVR
  • XFOOT (use %XFOOT)
• Comparison (use free form comparisons)
  • COMP
  • IFxx
  • WHENxx
• Flow control
  • DO
  • GOTO
• Parameters (use prototyped calls)
  • PARM
  • PLIST
• Other
  • TESTB
  • TESTN
  • TESTZ
  • XLATE (use %XLATE)

Example

C                   if        PCFRS = '*ALL'                
C                   eval      #CFRSF = *BLANK               
C                   eval      #CFRSH = *BLANK               
C                   else                                    
C                   eval      #CFRSF = i_CF_Const(PCFRS)    
C                   eval      #CFRSH = #CFRSF               
C                   endif                                   
                                                            
 /free                                                      
  if (pMOLS = '*ALL');                                      
    eval #MOLSF = *blank;                                   
    eval #MOLSH = *blank;                                   
  else;                                                     
    eval #MOLSF = pMOLS;                                    
    eval #MOLSH = pMOLS;                                    
  endif;                                                    
 /end-free                                             
     
C     C#RTNS        IFNE      '*EXITPGM'               
C     C#RTNS        ANDNE     '*RETURN'