protected static function readParameter(\Jstewmc\Stream\Stream $stream)
	{
		$parameter = '';
		
		// if the current character is a digit or hyphen ("-")
		if (ctype_digit($stream->current()) || $stream->current() == '-') {
			// determine if the parameter is negative
			$isNegative = ($stream->current() == '-'); 
			
			// if the number is negative, consume the hyphen
			if ($isNegative) {
				$stream->next();
			}
			
			// loop through the digits and append them to the parameter
			while (ctype_digit($stream->current())) {
				$parameter .= $stream->current();
				$stream->next();
			} 
						
			// evaluate the parameter's numeric value
			$parameter = +$parameter;
		
			// if the parameter is negative, negate it
			if ($isNegative) {
				$parameter = -$parameter;	
			}
		} else {
			throw new \InvalidArgumentException(
				__METHOD__."() expects the current element in parameter one, characters, "
					. "to be a digit or hyphen"
			);
		}
		
		return $parameter;
	}