anchor.diff:  fragment EscapeSequence: '\\' [btnfr"'\\];
   fragment StringCharacter: ~["\\] | EscapeSequence;
   
  +// Lexer elements
   String: '"' StringCharacter* '"';
   Number: Digit Digit*;
   Name: NameCharacter NameCharacter*;
  
positive.code: 
  // Other rules
  layer: EELAYER Number Number EELAYER END;
  libs: (LIBS Name)*;
  
  description: DESCR sheetSize=Name sheetWidth=Number sheetHeight=Number description_content* ENDDESCR;
  description_content: String | Number | Name;
  
negative.code: COMPONENT_START: '$Comp';
  COMPONENT_END: '$EndComp';
  
  // Hidden lexer elements (no token is generated)
  fragment NameCharacter: [a-zA-Z0-9$_.-];
  fragment Digit: [0-9];
  fragment SheetClass: [A-E];
  