anchor.diff:  	;
   
   portstmt	
  -	:	( portDeclInit | portDecl ) NEWLINE
  +	:	( portDeclInit | portDecl | namedRef ) NEWLINE
   	;	
   	
   portName 
  
positive.code: 	 |  expr (GT | GTE | LT | LTE) expr       #comparisonExpr
  	 |  expr ( EQ | NEQ ) expr                #equalityExpr
  	 |  fullyQualifiedType                    #typeExpr
  	 |  funcCall                              #inlineFuncCall
  	 |  path                                  #pathExpr
  	 |	NUMBER 								  #numExpr
  	 |  BOOLEAN_LITERAL						  #boolExpr
  	 |  STRING_LITERAL                        #stringExpr
  
negative.code:     |   funcDeclInit NEWLINE
      |   funcDecl NEWLINE
      |   anonExpr
      |   namedRef NEWLINE
      ;
  
  listLiteral
      :   LSQUARE argList? RSQUARE
      ;
  
  expr : '(' expr ')'						      #parensExpr
  