function follow_set( $s ){
		if( ! isset($this->follows[$s]) ){
			$type = $this->is_terminal($s) ? 'terminal' : 'non-terminal';
			trigger_error("No follow set for $type $s", E_USER_WARNING );
			return array();
		}
		return $this->follows[$s];
	}
function follow_set( $s ){
		if( ! isset($this->follows[$s]) ){
			$type = $this->is_terminal($s) ? 'terminal' : 'non-terminal';
			trigger_error("No follow set for $type $s", E_USER_WARNING );
			return array();
		}
		return $this->follows[$s];
	}
function follow_set ( $ s ) { if ( ! isset ( $ this -> follows [ $ s ] ) ) { $ type = $ this -> is_terminal ( $ s ) ? 'terminal' : 'non-terminal' ; trigger_error ( "No follow set for $type $s" , E_USER_WARNING ) ; return array ( ) ; } return $ this -> follows [ $ s ] ; }
Get FOLLOW set for a single given symbol
@param int scalar symbol
@return array set of terminal symbols
Get FOLLOW set for a single given symbol