This mode is selected by the $MODE MACPAS switch. On the command line, this mode is selected by
the -Mmacpas switch. It mainly switches on some extra features:
     
     - Support for the $SETC directive.
     
 
     - Support for the $IFC, $ELSEC and $ENDC directives.
     
 
     - Support for the UNDEFINED construct in macros.
     
 
     - Support for TRUE and FALSE as values in macro expressions.
     
 
     - Macros may be assigned hexadecimal numbers, like $2345.
     
 
     - The Implementation keyword can be omitted if the implementation section is empty.
     
 
     - The cdecl modifier keyword can be abbreviated to C.
     
 
     - UNIV modifier for types in parameter lists is supported.
     
 
     - ... (ellipsis) is allowed in procedure declarations, is functionally equal to the varargs
     keyword.
     
 
     - $MODESWITCH nestedprocvars is enabled by default.
 
(Note: Macros are called ’Compiler Variables’ in Mac OS dialects.)
Currently, the following Mac OS pascal extensions are not yet supported in MACPAS
mode:
     
     - External procedures declared in the interface must have the directive External, unless
     the unit has no Implementation section.
     
 
     - Cycle instead of Continue.
     
 
     - Leave instead of Break
                                                                            
                                                                            
     
 
     - Exit cannot have the name of the procedure to exit as parameter. Instead, for a function
     the value to return can be supplied as parameter.
     
 
     - No propagating uses.
     
 
     - Compiler directives defined in interface sections are not exported.