                                      PreProcessor

    There is no separate preprocessor pass.  The parser front-end calls Lex() which
    has the preprocessor built-in.  The compiler looks ahead a token, most of the
    time, so you might throw an extra semicolon after a directive if it's not taking
    affect right away.

    Put an extra semicolon #exe {Cd("DirName");;} in case a #include follows.

    #include ""     There is no angle bracket <> form of this directive.
    #exe {}         Will execute code at compile-time and can be used to insert code
    into the stream being compiled using StreamPrint().
    #define         Define string const
    #assert         Print a warning during compilation if an expression is not true.
    #if             Include code if an expresion is true.
    #else
    #endif
    #ifdef,#ifndef  Include code if a sym is defined.
    #ifaot,#ifjit   Include code if in AOT compiler mode.
    defined()       Is a function that can be used in expressions.
    #help_index, #help_file See Help System.

    See PreProcessor.