anchor.diff:  endIfStmt:  '{%' 'end' '%}' ;    
   
   /*
  -// TODO should be in the expr rule!
  +// TODO delete
   boolExpr:   expr op=('=='|'!='|'<'|'>'|'<='|'>=') expr    # exprComparison
           |   boolExpr op=('=='|'!=') boolExpr            # boolComparison
           |   boolExpr op=('and'|'or'|'&&'|'||') boolExpr    # boolExprCombination
  
positive.code: 
  /**
   * Output a variable (shortcut for {% print $var %})
   * Tags only are allowed. E.g: {{ $var|upper }}
   **/
  outputVariable: '{{' expr (END_OUTPUT|END_OUTPUT_WS) ;
  
  
negative.code:         ;
  
  postfixExpression
      :   atom //should be ID (and maybe allow STRING too)
      |   postfixExpression '[' expr ']'
      |   postfixExpression '(' argumentExpressionList? ')'
      |   postfixExpression '.' ID                            # attributeLookup 
  