anchor.diff:                  | '"'  ( ~('\n'|'\r'|'\f'|'"')  )* ( '"'  | { $type = INVALID; } )
                   ;
   
  -EXPRESSION_FUNC : E X P R E S S I O N ;
  -ALPHA_FUNC      : A L P H A           ;
  +// Some special identifiers
  +EXPRESSION : E X P R E S S I O N        ;
  +ALPHA      : A L P H A                  ;
   
   // -------------
   // Identifier.  Identifier tokens pick up properties names and values
  
positive.code: important
      : IMPORTANT_SYM
      ;
      
  expr 
      : term ((WS+|WS* operator WS*) term)*
      ;
  
  term
      : unaryOperator?
          (
                NUMBER
              | PERCENTAGE
  
negative.code:     | PLUS
      ;  
      
   */   
  
  hexColor 
      : HASH
      ;
      
  ident    
      : IDENT 
      | ALPHA 
      | EXPRESSION 
      ;
  
  // ==============================================================
  // LEXER
  //
  