Prolog "adapt"

         
/**
         
 * Warranty & Liability
         
 * To the extent permitted by applicable law and unless explicitly
         
 * otherwise agreed upon, XLOG Technologies AG makes no warranties
         
 * regarding the provided information. XLOG Technologies AG assumes
         
 * no liability that any problems might be solved with the information
         
 * provided by XLOG Technologies AG.
         
 *
         
 * Rights & License
         
 * All industrial property rights regarding the information - copyright
         
 * and patent rights in particular - are the sole property of XLOG
         
 * Technologies AG. If the company was not the originator of some
         
 * excerpts, XLOG Technologies AG has at least obtained the right to
         
 * reproduce, change and translate the information.
         
 *
         
 * Reproduction is restricted to the whole unaltered document. Reproduction
         
 * of the information is only allowed for non-commercial uses. Selling,
         
 * giving away or letting of the execution of the library is prohibited.
         
 * The library can be distributed as part of your applications and libraries
         
 * for execution provided this comment remains unchanged.
         
 *
         
 * Restrictions
         
 * Only to be distributed with programs that add significant and primary
         
 * functionality to the library. Not to be distributed with additional
         
 * software intended to replace any components of the library.
         
 *
         
 * Trademarks
         
 * Jekejeke is a registered trademark of XLOG Technologies AG.
         
 */
         

         
/************************************************************/
         
/* Single                                                   */
         
/************************************************************/
         

         
/* Single Trie */
         

         
/**
         
 * tree_current(P, K, T, V):
         
 * The predicate succceeds in V with the value at path P starting
         
 * from the level K in the adaptive tree T.
         
 */
         
% tree_current(+List, +Integer, +Tree, -Term)
         
tree_current([], _, R, R).
         
tree_current([_|L], K, N, R) :- (N = (I->_;_), K @< I; N \= (_;_)), !,
         
   J is K+1,
         
   tree_current(L, J, N, R).
         
tree_current([1|L], K, (K->A;_), R) :- !,
         
   J is K+1,
         
   tree_current(L, J, A, R).
         
tree_current([0|L], K, (K->_;B), R) :-
         
   J is K+1,
         
   tree_current(L, J, B, R).
         

         
/**
         
 * tree_set(P, K, T, V, S):
         
 * The predicate succeeds in S with the adaptive tree derived from
         
 * the adaptive tree T that has the value at path P starting from
         
 * the level K changed to the value V.
         
 */
         
% tree_set(+List, +Integer, +Tree, +Term, -Tree)
         
tree_set([], _, _, R, R).
         
tree_set([X|L], K, N, S, R) :- (N = (I->_;_), K @< I; N \= (_;_)), !,
         
   tree_set([X|L], K, (K ->N;N), S, R).
         
tree_set([1|L], K, (K->A;B), S, R) :- !,
         
   J is K+1,
         
   tree_set(L, J, A, S, C),
         
   tree_make(K, C, B, R).
         
tree_set([0|L], K, (K->A;B), S, R) :-
         
   J is K+1,
         
   tree_set(L, J, B, S, C),
         
   tree_make(K, A, C, R).
         

         
/**
         
 * tree_make(X, A, B, R).
         
 * The predicate succeeds in R with an adaptive tree that has
         
 * variable X and cofactors A and B, possibly reducing it.
         
 */
         
% tree_make(+Atom, +Tree, +Tree, -Tree)
         
tree_make(_, A, A, A) :- !.
         
tree_make(X, A, B, (X->A;B)).