/* Part of SWI-Prolog Author: Tom Schrijvers, Bart Demoen, Jan Wielemaker E-mail: Tom.Schrijvers@cs.kuleuven.be WWW: http://www.swi-prolog.org Copyright (C): 2004-2008, K.U. Leuven This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA As a special exception, if you link this library with other files, compiled with a Free Software compiler, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ :- module(hprolog, [ substitute_eq/4, % +OldVal, +OldList, +NewVal, -NewList memberchk_eq/2, % +Val, +List intersect_eq/3, % +List1, +List2, -Intersection list_difference_eq/3, % +List, -Subtract, -Rest take/3, % +N, +List, -FirstElements drop/3, % +N, +List, -LastElements split_at/4, % +N, +List, -FirstElements, -LastElements max_go_list/2, % +List, -Max or_list/2, % +ListOfInts, -BitwiseOr sublist/2, % ?Sublist, +List bounded_sublist/3, % ?Sublist, +List, +Bound chr_delete/3, init_store/2, get_store/2, update_store/2, make_get_store_goal/3, make_update_store_goal/3, make_init_store_goal/3, empty_ds/1, ds_to_list/2, get_ds/3, put_ds/4 % lookup_ht1/4 ]). :- reexport('../lists',[sublist/2]). %:- use_module(library(lists)). :- use_module(library(assoc)). /** hProlog compatibility library This library has been developed mainly for porting the CHR package. @author Tom Schrijvers @author Bart Demoen @author Jan Wielemaker @tbd Ultimately, this must disappear. Generally useful predicates must be moved to their appropriate library. Others must be moved into the CHR utilities. */ empty_ds(DS) :- empty_assoc(DS). ds_to_list(DS,LIST) :- assoc_to_list(DS,LIST). get_ds(A,B,C) :- get_assoc(A,B,C). put_ds(A,B,C,D) :- put_assoc(A,B,C,D). init_store(Name,Value) :- nb_setval(Name,Value). get_store(Name,Value) :- nb_getval(Name,Value). update_store(Name,Value) :- b_setval(Name,Value). make_init_store_goal(Name,Value,Goal) :- Goal = nb_setval(Name,Value). make_get_store_goal(Name,Value,Goal) :- Goal = nb_getval(Name,Value). make_update_store_goal(Name,Value,Goal) :- Goal = b_setval(Name,Value). /******************************* * MORE LIST OPERATIONS * *******************************/ %% substitute_eq(+OldVal, +OldList, +NewVal, -NewList) % % Substitute OldVal by NewVal in OldList and unify the result % with NewList. substitute_eq(_, [], _, []) :- ! . substitute_eq(X, [U|Us], Y, [V|Vs]) :- ( X == U -> V = Y, substitute_eq(X, Us, Y, Vs) ; V = U, substitute_eq(X, Us, Y, Vs) ). %% memberchk_eq(+Val, +List) % % Deterministic check of membership using == rather than % unification. memberchk_eq(X, [Y|Ys]) :- ( X == Y -> true ; memberchk_eq(X, Ys) ). % :- load_foreign_library(chr_support). %% list_difference_eq(+List, -Subtract, -Rest) % % Delete all elements of Subtract from List and unify the result % with Rest. Element comparision is done using ==/2. list_difference_eq([],_,[]). list_difference_eq([X|Xs],Ys,L) :- ( memberchk_eq(X,Ys) -> list_difference_eq(Xs,Ys,L) ; L = [X|T], list_difference_eq(Xs,Ys,T) ). %% intersect_eq(+List1, +List2, -Intersection) % % Determine the intersection of two lists without unifying values. intersect_eq([], _, []). intersect_eq([X|Xs], Ys, L) :- ( memberchk_eq(X, Ys) -> L = [X|T], intersect_eq(Xs, Ys, T) ; intersect_eq(Xs, Ys, L) ). %% take(+N, +List, -FirstElements) % % Take the first N elements from List and unify this with % FirstElements. The definition is based on the GNU-Prolog lists % library. Implementation by Jan Wielemaker. take(0, _, []) :- !. take(N, [H|TA], [H|TB]) :- N > 0, N2 is N - 1, take(N2, TA, TB). %% drop(+N, +List, -ListMinFirstN) is semidet. % % Drop the first N elements from List and unify the remainder with % LastElements. drop(0,LastElements,LastElements) :- !. drop(N,[_|Tail],LastElements) :- N > 0, N1 is N - 1, drop(N1,Tail,LastElements). %% split_at(+N, +List, +FirstN, -Rest) is semidet. % % Combines take/3 and drop/3. split_at(0,L,[],L) :- !. split_at(N,[H|T],[H|L1],L2) :- M is N -1, split_at(M,T,L1,L2). %% max_go_list(+List, -Max) % % Return the maximum of List in the standard order of terms. max_go_list([H|T], Max) :- max_go_list(T, H, Max). max_go_list([], Max, Max). max_go_list([H|T], X, Max) :- ( H @=< X -> max_go_list(T, X, Max) ; max_go_list(T, H, Max) ). %% or_list(+ListOfInts, -BitwiseOr) % % Do a bitwise disjuction over all integer members of ListOfInts. or_list(L, Or) :- or_list(L, 0, Or). or_list([], Or, Or). or_list([H|T], Or0, Or) :- Or1 is H \/ Or0, or_list(T, Or1, Or). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% sublist(?Sub, +List) is nondet. % % True if all elements of Sub appear in List in the same order. %sublist(L, L). %sublist(Sub, [H|T]) :- % '$sublist1'(T, H, Sub). %'$sublist1'(Sub, _, Sub). %'$sublist1'([H|T], _, Sub) :- % '$sublist1'(T, H, Sub). %'$sublist1'([H|T], X, [X|Sub]) :- % '$sublist1'(T, H, Sub). %% bounded_sublist(?Sub, +List, +Bound:integer) % % As sublist/2, but Sub has at most Bound elements. E.g. the call % below generates all 21 sublists of length =< 2 from the second % argument. % % == % ?- bounded_sublist(List, [a,b,c,d], 2). % X = [] ; % X = [a] ; % X = [a, b] ; % X = [a] ; % ... % == bounded_sublist(Sublist,_,_) :- Sublist = []. bounded_sublist(Sublist,[H|List],Bound) :- Bound > 0, ( Sublist = [H|Rest], NBound is Bound - 1, bounded_sublist(Rest,List,NBound) ; bounded_sublist(Sublist,List,Bound) ). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% chr_delete(+List, +Element, -Rest) is det. % % Rest is a copy of List without elements matching Element using % ==. chr_delete([], _, []). chr_delete([H|T], X, L) :- ( H==X -> chr_delete(T, X, L) ; L=[H|RT], chr_delete(T, X, RT) ).