Before the contents of the source file is handed to the main parser, it goes through the preprocessor. The preprocessor knows nothing of mnemonics or the script language. It's a simple mechanism that enables you to select pieces of the source to be discarded or included in what the main parser sees. This chapter explains how. (NOTE: The preprocessor is made like the one used in C# with the addition of #import, #importif and #importonce so you might find this familiar)
The preprocessor uses symbols do determine if it should discard or include portions of the source file. There are two methods to define a symbol. The first is from the command line. This defines a symbol called 'TEST':
java -jar KickAss.jar -define TEST
A symbol is either defined or not defined. It has no assigned value.
The other way is using the #define directive:
#define TEST
You can recognize a preprocessor directive on the '#'. If the first non-whitespace character on a line is a '#' then the line is a call to the preprocessor. If you want to remove the definition of a symbol you use the #undef directive.
#undef TEST