public SelectorNode parse ( ) throws InvalidSelectorException { if ( isEndOfExpression ( ) ) return null ; SelectorNode expr = parseExpression ( ) ; if ( ! isEndOfExpression ( ) ) throw new InvalidSelectorException ( "Unexpected token : " + currentToken ) ; if ( ! ( expr instanceof ConditionalExpression ) ) throw new InvalidSelectorException ( "Selector expression is not a boolean expression" ) ; return expr ; }
Parse the given message selector expression into a selector node tree