=========================
Parser (No Parameters)
=========================
parser simple() {
  state start {
    transition accept;
  }
};

---
(p4program
 (declaration
  (parserDeclaration
   (parserType
    (parser)
    (identifier)
   )
   (parserStates
    (parserState
     (state)
     (identifier)
     (parserTransitionStatement
      (transition)
      (transitionSelectionExpression
       (identifier)
      )
     )
     (semicolon)
    )
   )
  )
 )
 (semicolon)
)


=========================
Parser (Parameters)
=========================
parser imple(bool pname) {
  state start {
    transition accept;
  }
};

---
(p4program
 (declaration
  (parserDeclaration
   (parserType
    (parser)
    (identifier)
    (parameterList
     (parameter
      (typeRef
       (baseType
        (bool)
       )
      )
      (identifier)
     )
    )
   )
   (parserStates
    (parserState
     (state)
     (identifier)
     (parserTransitionStatement
      (transition)
      (transitionSelectionExpression
       (identifier)
      )
     )
     (semicolon)
    )
   )
  )
 )
 (semicolon)
)