Preprocessor directives

Preprocessor directives can be used in Genero BDL sources.

Genero BDL supports preprocessing instructions, which allow you to write macros and conditional compilation rules as in the following example:

&include "myheader.4gl"
FUNCTION debug( msg )
  DEFINE msg STRING
&ifdef DEBUG
  DISPLAY msg 
&endif
END FUNCTION

Use the preprocessor with care, and only when there is no native language solution. Too many preprocessing directives make the code unreadable and unmaintainable.