Interface for qBeta module object

Origin: ExpressionGrammar

expParser: obj
   %visible expAst
   next:
   exp:
      out N: ref Node:left:right
   term:
      out N: ref node:left:right
   primary:
      out N: ref Node:left:right
   number:
      out N: ref node:left:right
   digit:
      out N: ref Node:left:right
   syntaxError:
   parse:
      N: ref Node:left:right
   inn: ref String
   pos: var integer
   ch: var integer