/* $Id$ Part of CHR (Constraint Handling Rules) Author: Tom Schrijvers and Jan Wielemaker E-mail: Tom.Schrijvers@cs.kuleuven.be WWW: http://www.swi-prolog.org Copyright (C): 2003-2004, 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 Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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. */ %% SWI begin :- module(chr, [ op(1180, xfx, ==>), op(1180, xfx, <=>), op(1150, fx, constraints), op(1150, fx, chr_constraint), op(1150, fx, chr_preprocessor), op(1150, fx, handler), op(1150, fx, rules), op(1100, xfx, \), op(1200, xfx, @), op(1190, xfx, pragma), op( 500, yfx, #), op(1150, fx, chr_type), op(1150, fx, chr_declaration), op(1130, xfx, --->), op(1150, fx, (?)), chr_show_store/1, % +Module find_chr_constraint/1, % +Pattern chr_trace/0, chr_notrace/0, chr_leash/1 % +Ports ]). :- expects_dialect(swi). :- set_prolog_flag(generate_debug_info, false). :- multifile user:file_search_path/2. :- dynamic user:file_search_path/2. :- dynamic chr_translated_program/1. user:file_search_path(chr, library(chr)). :- load_files([ chr(chr_translate), chr(chr_runtime), chr(chr_messages), chr(chr_hashtable_store), chr(chr_compiler_errors) ], [ if(not_loaded), silent(true) ]). :- use_module(library(lists),[member/2]). %% SWI end %% SICStus begin %% :- module(chr,[ %% chr_trace/0, %% chr_notrace/0, %% chr_leash/0, %% chr_flag/3, %% chr_show_store/1 %% ]). %% %% :- op(1180, xfx, ==>), %% op(1180, xfx, <=>), %% op(1150, fx, constraints), %% op(1150, fx, handler), %% op(1150, fx, rules), %% op(1100, xfx, \), %% op(1200, xfx, @), %% op(1190, xfx, pragma), %% op( 500, yfx, #), %% op(1150, fx, chr_type), %% op(1130, xfx, --->), %% op(1150, fx, (?)). %% %% :- multifile user:file_search_path/2. %% :- dynamic chr_translated_program/1. %% %% user:file_search_path(chr, library(chr)). %% %% %% :- use_module('chr/chr_translate'). %% :- use_module('chr/chr_runtime'). %% :- use_module('chr/chr_hashtable_store'). %% :- use_module('chr/hprolog'). %% SICStus end :- multifile chr:'$chr_module'/1. :- dynamic chr_term/3. % File, Term :- dynamic chr_pp/2. % File, Term % chr_expandable(+Term) % % Succeeds if Term is a rule that must be handled by the CHR % compiler. Ideally CHR definitions should be between % % :- constraints ... % ... % :- end_constraints. % % As they are not we have to use some heuristics. We assume any % file is a CHR after we've seen :- constraints ... chr_expandable((:- constraints _)). chr_expandable((constraints _)). chr_expandable((:- chr_constraint _)). chr_expandable((:- chr_type _)). chr_expandable((chr_type _)). chr_expandable((:- chr_declaration _)). chr_expandable(option(_, _)). chr_expandable((:- chr_option(_, _))). chr_expandable((handler _)). chr_expandable((rules _)). chr_expandable((_ <=> _)). chr_expandable((_ @ _)). chr_expandable((_ ==> _)). chr_expandable((_ pragma _)). % chr_expand(+Term, -Expansion) % % Extract CHR declarations and rules from the file and run the % CHR compiler when reaching end-of-file. %% SWI begin extra_declarations([ (:- use_module(chr(chr_runtime))), (:- style_check(-discontiguous)), (:- style_check(-singleton)), (:- style_check(-no_effect)), (:- set_prolog_flag(generate_debug_info, false)) | Tail ], Tail). %% SWI end %% SICStus begin %% extra_declarations([(:-use_module(chr(chr_runtime))) %% , (:- use_module(chr(hprolog),[term_variables/2,term_variables/3])) %% , (:-use_module(chr(hpattvars))) %% | Tail], Tail). %% SICStus end chr_expand(Term, []) :- chr_expandable(Term), !, prolog_load_context(source,File), prolog_load_context(term_position,Pos), stream_position_data(line_count,Pos,LineNumber), add_pragma_to_chr_rule(Term,line_number(LineNumber),NTerm), assert(chr_term(File, LineNumber, NTerm)). chr_expand(Term, []) :- Term = (:- chr_preprocessor Preprocessor), !, prolog_load_context(source,File), assert(chr_pp(File, Preprocessor)). chr_expand(end_of_file, FinalProgram) :- extra_declarations(FinalProgram,Program), prolog_load_context(source,File), findall(T, retract(chr_term(File,_Line,T)), CHR0), CHR0 \== [], prolog_load_context(module, Module), add_debug_decl(CHR0, CHR1), add_optimise_decl(CHR1, CHR2), CHR3 = [ (:- module(Module, [])) | CHR2 ], findall(P, retract(chr_pp(File, P)), Preprocessors), ( Preprocessors = [] -> CHR3 = CHR ; Preprocessors = [Preprocessor] -> chr_compiler_errors:chr_info(preprocessor,'\tPreprocessing with ~w.\n',[Preprocessor]), call_chr_preprocessor(Preprocessor,CHR3,CHR) ; chr_compiler_errors:print_chr_error(error(syntax(Preprocessors),'Too many preprocessors! Only one is allowed!\n',[])), fail ), catch(call_chr_translate(File, [ (:- module(Module, [])) | CHR ], Program0), chr_error(Error), ( chr_compiler_errors:print_chr_error(Error), fail ) ), delete_header(Program0, Program). delete_header([(:- module(_,_))|T0], T) :- !, delete_header(T0, T). delete_header(L, L). add_debug_decl(CHR, CHR) :- member(option(Name, _), CHR), Name == debug, !. add_debug_decl(CHR, CHR) :- member((:- chr_option(Name, _)), CHR), Name == debug, !. add_debug_decl(CHR, [(:- chr_option(debug, Debug))|CHR]) :- ( chr_current_prolog_flag(generate_debug_info, true) -> Debug = on ; Debug = off ). %% SWI begin chr_current_prolog_flag(Flag,Val) :- current_prolog_flag(Flag,Val). %% SWI end add_optimise_decl(CHR, CHR) :- \+(\+(memberchk((:- chr_option(optimize, _)), CHR))), !. add_optimise_decl(CHR, [(:- chr_option(optimize, full))|CHR]) :- chr_current_prolog_flag(optimize, full), !. add_optimise_decl(CHR, CHR). % call_chr_translate(+File, +In, -Out) % % The entire chr_translate/2 translation may fail, in which case we'd % better issue a warning rather than simply ignoring the CHR % declarations. call_chr_translate(File, In, _Out) :- ( chr_translate_line_info(In, File, Out0) -> nb_setval(chr_translated_program,Out0), fail ). call_chr_translate(_, _In, Out) :- nb_current(chr_translated_program,Out), !, nb_delete(chr_translated_program). call_chr_translate(File, _, []) :- print_message(error, chr(compilation_failed(File))). call_chr_preprocessor(Preprocessor,CHR,_NCHR) :- ( call(Preprocessor,CHR,CHR0) -> nb_setval(chr_preprocessed_program,CHR0), fail ). call_chr_preprocessor(_,_,NCHR) :- nb_current(chr_preprocessed_program,NCHR), !, nb_delete(chr_preprocessed_program). call_chr_preprocessor(Preprocessor,_,_) :- chr_compiler_errors:print_chr_error(error(preprocessor,'Preprocessor `~w\' failed!\n',[Preprocessor])). %% SWI begin /******************************* * SYNCHRONISE TRACER * *******************************/ :- multifile user:message_hook/3, chr:debug_event/2, chr:debug_interact/3. :- dynamic user:message_hook/3. user:message_hook(trace_mode(OnOff), _, _) :- ( OnOff == on -> chr_trace ; chr_notrace ), fail. % backtrack to other handlers % chr:debug_event(+State, +Event) % % Hook into the CHR debugger. At this moment we will discard CHR % events if we are in a Prolog `skip' and we ignore the chr:debug_event(_State, _Event) :- tracing, % are we tracing? prolog_skip_level(Skip, Skip), Skip \== very_deep, prolog_current_frame(Me), prolog_frame_attribute(Me, level, Level), Level > Skip, !. % chr:debug_interact(+Event, +Depth, -Command) % % Hook into the CHR debugger to display Event and ask for the next % command to execute. This definition causes the normal Prolog % debugger to be used for the standard ports. chr:debug_interact(Event, _Depth, creep) :- prolog_event(Event), tracing, !. prolog_event(call(_)). prolog_event(exit(_)). prolog_event(fail(_)). /******************************* * MESSAGES * *******************************/ :- multifile prolog:message/3. prolog:message(chr(CHR)) --> chr_message(CHR). :- multifile check:trivial_fail_goal/1. check:trivial_fail_goal(_:Goal) :- functor(Goal, Name, _), sub_atom(Name, 0, _, _, '$chr_store_constants_'). /******************************* * TOPLEVEL PRINTING * *******************************/ :- create_prolog_flag(chr_toplevel_show_store, true, []). prolog:message(query(YesNo)) --> !, ['~@'-[chr:print_all_stores]], '$messages':prolog_message(query(YesNo)). prolog:message(query(YesNo,Bindings)) --> !, ['~@'-[chr:print_all_stores]], '$messages':prolog_message(query(YesNo,Bindings)). print_all_stores :- ( chr_current_prolog_flag(chr_toplevel_show_store,true), catch(nb_getval(chr_global, _), _, fail), chr:'$chr_module'(Mod), chr_show_store(Mod), fail ; true ). /******************************* * MUST BE LAST! * *******************************/ :- multifile system:term_expansion/2. :- dynamic system:term_expansion/2. system:term_expansion(In, Out) :- \+ current_prolog_flag(xref, true), chr_expand(In, Out). %% SWI end %% SICStus begin % % :- dynamic % current_toplevel_show_store/1, % current_generate_debug_info/1, % current_optimize/1. % % current_toplevel_show_store(on). % % current_generate_debug_info(false). % % current_optimize(off). % % chr_current_prolog_flag(generate_debug_info, X) :- % chr_flag(generate_debug_info, X, X). % chr_current_prolog_flag(optimize, X) :- % chr_flag(optimize, X, X). % % chr_flag(Flag, Old, New) :- % Goal = chr_flag(Flag,Old,New), % g must_be(Flag, oneof([toplevel_show_store,generate_debug_info,optimize]), Goal, 1), % chr_flag(Flag, Old, New, Goal). % % chr_flag(toplevel_show_store, Old, New, Goal) :- % clause(current_toplevel_show_store(Old), true, Ref), % ( New==Old -> true % ; must_be(New, oneof([on,off]), Goal, 3), % erase(Ref), % assertz(current_toplevel_show_store(New)) % ). % chr_flag(generate_debug_info, Old, New, Goal) :- % clause(current_generate_debug_info(Old), true, Ref), % ( New==Old -> true % ; must_be(New, oneof([false,true]), Goal, 3), % erase(Ref), % assertz(current_generate_debug_info(New)) % ). % chr_flag(optimize, Old, New, Goal) :- % clause(current_optimize(Old), true, Ref), % ( New==Old -> true % ; must_be(New, oneof([full,off]), Goal, 3), % erase(Ref), % assertz(current_optimize(New)) % ). % % % all_stores_goal(Goal, CVAs) :- % chr_flag(toplevel_show_store, on, on), !, % findall(C-CVAs, find_chr_constraint(C), Pairs), % andify(Pairs, Goal, CVAs). % all_stores_goal(true, _). % % andify([], true, _). % andify([X-Vs|L], Conj, Vs) :- andify(L, X, Conj, Vs). % % andify([], X, X, _). % andify([Y-Vs|L], X, (X,Conj), Vs) :- andify(L, Y, Conj, Vs). % % :- multifile user:term_expansion/6. % % user:term_expansion(In, _, Ids, Out, [], [chr|Ids]) :- % nonvar(In), % nonmember(chr, Ids), % chr_expand(In, Out), !. % %% SICStus end %%% for SSS %%% add_pragma_to_chr_rule((Name @ Rule), Pragma, Result) :- !, add_pragma_to_chr_rule(Rule,Pragma,NRule), Result = (Name @ NRule). add_pragma_to_chr_rule((Rule pragma Pragmas), Pragma, Result) :- !, Result = (Rule pragma (Pragma,Pragmas)). add_pragma_to_chr_rule((Head ==> Body), Pragma, Result) :- !, Result = (Head ==> Body pragma Pragma). add_pragma_to_chr_rule((Head <=> Body), Pragma, Result) :- !, Result = (Head <=> Body pragma Pragma). add_pragma_to_chr_rule(Term,_,Term).