Chris@82: (*
Chris@82:  * Copyright (c) 1997-1999 Massachusetts Institute of Technology
Chris@82:  * Copyright (c) 2003, 2007-14 Matteo Frigo
Chris@82:  * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
Chris@82:  *
Chris@82:  * This program is free software; you can redistribute it and/or modify
Chris@82:  * it under the terms of the GNU General Public License as published by
Chris@82:  * the Free Software Foundation; either version 2 of the License, or
Chris@82:  * (at your option) any later version.
Chris@82:  *
Chris@82:  * This program is distributed in the hope that it will be useful,
Chris@82:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@82:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@82:  * GNU General Public License for more details.
Chris@82:  *
Chris@82:  * You should have received a copy of the GNU General Public License
Chris@82:  * along with this program; if not, write to the Free Software
Chris@82:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
Chris@82:  *
Chris@82:  *)
Chris@82: 
Chris@82: type ('a, 'b) elem =
Chris@82:   | Leaf
Chris@82:   | Node of int * ('a, 'b) elem * ('a, 'b) elem * ('a * 'b) list
Chris@82: val empty : ('a, 'b) elem
Chris@82: val lookup :
Chris@82:     ('a -> int) -> ('a -> 'b -> bool) -> 'a -> ('b, 'c) elem -> 'c option
Chris@82: val insert :
Chris@82:     ('a -> int) -> 'a -> 'c -> ('a, 'c) elem -> ('a, 'c) elem