/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: http://www.swi-prolog.org Copyright (c) 2019-2021, VU University Amsterdam SWI-Prolog Solutions b.v. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(increval, [ incr_assert/1, % :Clause incr_asserta/1, % :Clause incr_assertz/1, % :Clause incr_retractall/1, % :Head incr_retract/1, % :Clause is_incremental_subgoal/1, % :Goal incr_directly_depends/2, % :Goal1, :Goal2 incr_trans_depends/2, % :Goal1, :Goal2 incr_invalid_subgoals/1, % -List incr_is_invalid/1, % :Goal incr_invalidate_call/1, % :Goal incr_invalidate_calls/1, % :Goal incr_table_update/0, incr_propagate_calls/1 % :Answer ]). :- use_module(library(tables)). /** Incremental dynamic predicate modification This module emulates the XSB module `increval`. This module serves two goals: (1) provide alternatives for the dynamic clause manipulation predicates that propagate into the incremental tables and (2) query the dynamically maintained _Incremental Depency Graph_ (IDG). The change propagation for incremental dynamic predicates. SWI-Prolog relies in prolog_listen/2 to forward any change to dynamic predicates to the table IDG and incr_assert/1 and friends thus simply call the corresponding database update. @compat XSB */ :- meta_predicate incr_assert(:), incr_asserta(:), incr_assertz(:), incr_retractall(:), incr_retract(:), is_incremental_subgoal(:), incr_directly_depends(:,:), incr_trans_depends(:, :), incr_is_invalid(:), incr_invalidate_call(:), incr_invalidate_calls(:), incr_propagate_calls(:). incr_assert(T) :- assertz(T). incr_asserta(T) :- asserta(T). incr_assertz(T) :- assertz(T). incr_retractall(T) :- retractall(T). incr_retract(T) :- retract(T). %! is_incremental_subgoal(?SubGoal) is nondet. % % This predicate non-deterministically unifies Subgoal with % incrementally tabled subgoals that are currently table entries. is_incremental_subgoal(SubGoal) :- '$tbl_variant_table'(VTrie), trie_gen(VTrie, SubGoal, ATrie), ( '$idg_edge'(ATrie, _Dir, _Value) -> true ). %! incr_directly_depends(:Goal1, :Goal2) is nondet. % % True if Goal1 depends on Goal2 in the IDG. % % @compat: In XSB, at least one of Goal 1 or Goal 2 must be bound. % This implementation may be used with both arguments unbound. incr_directly_depends(Goal1, Goal2) :- '$tbl_variant_table'(VTrie), ( nonvar(Goal2) -> trie_gen(VTrie, Goal2, ATrie2), '$idg_edge'(ATrie2, affected, ATrie1), '$tbl_table_status'(ATrie1, _Status, Goal1, _Return) ; trie_gen(VTrie, Goal1, ATrie1), '$idg_edge'(ATrie1, dependent, ATrie2), '$tbl_table_status'(ATrie2, _Status, Goal2, _Return) ). %! incr_trans_depends(:Goal1, Goal2) is nondet. % % True for each pair in the transitive closure of % incr_directly_depends(G1, G2). incr_trans_depends(Goal1, Goal2) :- '$tbl_variant_table'(VTrie), ( nonvar(Goal1) -> trie_gen(VTrie, Goal1, ATrie1), incr_trans_depends(ATrie1, dependent, ATrie2, []), '$tbl_table_status'(ATrie2, _Status, Goal2, _Return) ; trie_gen(VTrie, Goal2, ATrie2), incr_trans_depends(ATrie2, affected, ATrie1, []), '$tbl_table_status'(ATrie1, _Status, Goal1, _Return) ). incr_trans_depends(ATrie1, Dir, ATrie, Done) :- '$idg_edge'(ATrie1, Dir, ATrie2), \+ memberchk(ATrie2, Done), ( ATrie = ATrie2 ; incr_trans_depends(ATrie2, Dir, ATrie, [ATrie2|Done]) ). %! incr_invalid_subgoals(-List) is det. % % List is a sorted list (set) of the incremental subgoals that are % currently invalid. incr_invalid_subgoals(List) :- findall(Invalid, invalid_subgoal(Invalid, _), List0), sort(List0, List). invalid_subgoal(Goal, ATrie) :- '$tbl_variant_table'(VTrie), trie_gen(VTrie, Goal, ATrie), ( '$idg_edge'(ATrie, _Dir, _Value) -> true ), '$idg_falsecount'(ATrie, Count), Count > 0, \+ '$tbl_table_status'(ATrie, dynamic, _Goal, _Return). %! incr_is_invalid(:Subgoal) is semidet. % % True when Subgoal's table is marked as invalid. incr_is_invalid(Subgoal) :- get_calls(Subgoal, Table, _Return), '$idg_falsecount'(Table, Count), Count > 0. %! incr_invalidate_calls(:Goal) is det. % % Invalidate all tables for subgoals of Goal as well as tables that % are affected by these. incr_invalidate_calls(Goal) :- '$tbl_variant_table'(VTable), !, forall(trie_gen(VTable, Goal, ATrie), '$idg_changed'(ATrie)). incr_invalidate_calls(_). %! incr_invalidate_call(:Goal) is det. % % This is the XSB name, but the manual says incr_invalidate_calls/1 % and the comment with the code suggests this is misnamed. % % @deprecated Use incr_invalidate_calls/1. incr_invalidate_call(Goal) :- incr_invalidate_calls(Goal). %! incr_table_update % % Updated all invalid tables incr_table_update :- repeat, ( invalid_subgoal(Goal, ATrie) -> '$tabling':reeval(ATrie, Goal, _Return), fail ; ! ). %! incr_propagate_calls(:Answer) is det. % % Activate the monotonic answer propagation similarly to when a new % fact is asserted for a monotonic dynamic predicate. The Answer term % must match a monotonic dynamic predicate. incr_propagate_calls(Answer) :- setup_call_cleanup( '$tbl_propagate_start'(Old), '$tabling':incr_propagate_assert(Answer), '$tbl_propagate_end'(Old)).