Macros

MP allows you to use macros, just like FPC, except that macros are always enabled.

 {$macro on}
 {$macro off}
 {$macro+}
 {$macro-} 

The {$macro on} directive is required by FPC, in MP it is retained for compatibility purposes only.

Defining a macro

{$define label := expression}

{$define label(par0, par1 ... par7) := expression}

For a definition to be recognized as a macro, the assignment symbol := must occur after the label name and any (par0..par7) parameter list.

{$define new_proc :=

procedure test;
begin

 writeln('ok');

end;
}


  new_proc


begin

 test;

end.
{$define sum_xi

 :=

 x:=x+i;
 }

begin

 sum_xi;

end;
{$define WIDTH := 80}
{$define LEN   :=   ( WIDTH + 10 )}

var a: byte;

begin

 a := len * 20;

end.

Macros with parameters are supported by MP but not by FPC, keep this in mind if you intend to test code on other hardware platforms.

{$define SIGN_MASK := $8000}
{$define SIGNED_INF_VALUE(x) := ((x and SIGN_MASK) or $7C00)}

var a: byte = 11;

begin

 writeln( SIGNED_INF_VALUE(a shl 15) );

end.