anchor.diff:              
   value_list: value ( value )*;
   
  -value : (VARIABLE | IDENTIFIER | STRING | integer ( DIMENSION | PERCENT)? );
  +value : (VARIABLE | IDENTIFIER | string | integer ( DIMENSION | PERCENT)? );
   
   integer: (PLUS | MINUS)? DIGITS;
   
  
positive.code: binomial: integer IDENTIFIER (PLUS DIGITS)?;
  
  //attribute_selector: parser.cpp:517
  attribute_selector: LSQBRACKET type_selector ((TILDE | PIPE | STAR | CARET | DOLLAR)? EQUALS (STRING | IDENTIFIER))? RSQBRACKET;
  
  type_selector: namespace_prefix? IDENTIFIER;
  
  
negative.code: WS : (' ' | '\t' | NL) -> skip;
  COMMENT: '/*' .*? '*/' -> skip;
  LINE_COMMENT : '//' ~[\r\n]* NL? -> skip;
  DSTRING : '"' ('\\"' | ~'"')* '"';
  SSTRING : '\'' ('\\\'' | ~'\'')* '\'';
  URL : 'url(' ~[)]* ')';
  COMMA : ',';
  SEMICOLON: ';';
  