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    1/*  Part of SWI-Prolog
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  1985-2017, University of Amsterdam
    7                              VU University Amsterdam
    8    All rights reserved.
    9
   10    Redistribution and use in source and binary forms, with or without
   11    modification, are permitted provided that the following conditions
   12    are met:
   13
   14    1. Redistributions of source code must retain the above copyright
   15       notice, this list of conditions and the following disclaimer.
   16
   17    2. Redistributions in binary form must reproduce the above copyright
   18       notice, this list of conditions and the following disclaimer in
   19       the documentation and/or other materials provided with the
   20       distribution.
   21
   22    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   23    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   24    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   25    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   26    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   27    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   28    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   29    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   30    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   31    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   32    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   33    POSSIBILITY OF SUCH DAMAGE.
   34*/
   35
   36:- module(backward_compatibility,
   37          [ '$arch'/2,
   38            '$version'/1,
   39            '$home'/1,
   40            '$argv'/1,
   41            '$set_prompt'/1,
   42            '$strip_module'/3,
   43            '$declare_module'/3,
   44            '$module'/2,
   45            at_initialization/1,        % :Goal
   46            displayq/1,
   47            displayq/2,
   48            sformat/2,                  % -String, +Fmt
   49            sformat/3,                  % -String, +Fmt, +Args
   50            concat/3,
   51            concat_atom/2,              % +List, -Atom
   52            concat_atom/3,              % +List, +Sep, -Atom
   53            '$apropos_match'/2,         % +Needle, +Hashstack
   54            read_clause/1,              % -Term
   55            read_clause/2,              % +Stream, -Term
   56            read_variables/2,           % -Term, -VariableNames
   57            read_variables/3,           % +Stream, -Term, -VariableNames
   58            read_pending_input/3,       % +Stream, -List, ?Tail
   59            feature/2,
   60            set_feature/2,
   61            substring/4,
   62            string_to_list/2,           % ?String, ?Codes
   63            string_to_atom/2,           % ?String, ?Atom
   64            flush/0,
   65            write_ln/1,                 % +Term
   66            proper_list/1,              % @Term
   67            free_variables/2,           % +Term, -Variables
   68            hash_term/2,                % +Term, -Hash
   69            checklist/2,                % :Goal, +List
   70            sublist/3,                  % :Goal, +List, -Sublist
   71            sumlist/2,                  % +List, -Sum
   72            convert_time/2,             % +Stamp, -String
   73            convert_time/8,             % +String, -YMDmhs.ms
   74            'C'/3,                      % +List, -Head, -Tail
   75            current_thread/2,           % ?Thread, ?Status
   76            current_mutex/3,            % ?Mutex, ?Owner, ?Count
   77            message_queue_size/2,       % +Queue, -TermsWaiting
   78            lock_predicate/2,           % +Name, +Arity
   79            unlock_predicate/2,         % +Name, +Arity
   80            current_module/2,           % ?Module, ?File
   81            export_list/2,              % +Module, -Exports
   82            setup_and_call_cleanup/3,   % :Setup, :Goal, :Cleanup
   83            setup_and_call_cleanup/4,   % :Setup, :Goal, ?Catcher, :Cleanup
   84            merge/3,                    % +List1, +List2, -Union
   85            merge_set/3,                % +Set1, +Set2, -Union
   86            (index)/1,                  % :Head
   87            hash/1,                     % :PI
   88            set_base_module/1,          % :Base
   89            eval_license/0,
   90            trie_insert_new/3,		% +Trie, +Term, -Node
   91            thread_at_exit/1            % :Goal
   92          ]).   93:- autoload(library(apply),[maplist/3,maplist/2]).   94:- autoload(library(lists),[sum_list/2]).   95:- autoload(library(system),[lock_predicate/1,unlock_predicate/1]).   96
   97
   98:- meta_predicate
   99    at_initialization(0),
  100    setup_and_call_cleanup(0,0,0),
  101    setup_and_call_cleanup(0,0,?,0),
  102    checklist(1, +),
  103    sublist(1, +, ?),
  104    index(:),
  105    hash(:),
  106    set_base_module(:),
  107    thread_at_exit(0).

Backward compatibility

This library defines predicates that used to exist in older version of SWI-Prolog, but are considered obsolete as there functionality is neatly covered by new features. Most often, these constructs are superceeded by ISO-standard compliant predicates.

Please also note the existence of quintus.pl and edinburgh.pl for more compatibility predicates.

See also
- gxref/0 can be used to find files that import from library(backcomp) and thus reply on deprecated features. */
 $arch(-Architecture, -Version) is det
deprecated
- use current_prolog_flag(arch, Architecture)
  127'$arch'(Arch, unknown) :-
  128    current_prolog_flag(arch, Arch).
 $version(Version:integer) is det
deprecated
- use current_prolog_flag(version, Version)
  134'$version'(Version) :-
  135    current_prolog_flag(version, Version).
 $home(-SWIPrologDir) is det
See also
- file_search_path/2, absolute_file_name/3, The Prolog home directory is available through the alias swi.
deprecated
- use current_prolog_flag(home, SWIPrologDir)
  143'$home'(Home) :-
  144    current_prolog_flag(home, Home).
 $argv(-Argv:list) is det
deprecated
- use current_prolog_flag(os_argv, Argv) or current_prolog_flag(argv, Argv)
  151'$argv'(Argv) :-
  152    current_prolog_flag(os_argv, Argv).
 $set_prompt(+Prompt) is det
Set the prompt for the toplevel
deprecated
- use set_prolog_flag(toplevel_prompt, Prompt).
  160'$set_prompt'(Prompt) :-
  161    (   is_list(Prompt)
  162    ->  Prompt0 = Prompt
  163    ;   atom_codes(Prompt, Prompt0)
  164    ),
  165    maplist(percent_to_tilde, Prompt0, Prompt1),
  166    atom_codes(Atom, Prompt1),
  167    set_prolog_flag(toplevel_prompt, Atom).
  168
  169percent_to_tilde(0'%, 0'~) :- !.
  170percent_to_tilde(X, X).
 displayq(@Term) is det
 displayq(+Stream, @Term) is det
Write term ignoring operators and quote atoms.
deprecated
- Use write_term/3 or write_canonical/2.
  180displayq(Term) :-
  181    write_term(Term, [ignore_ops(true),quoted(true)]).
  182displayq(Stream, Term) :-
  183    write_term(Stream, Term, [ignore_ops(true),quoted(true)]).
 sformat(-String, +Format, +Args) is det
 sformat(-String, +Format) is det
deprecated
- Use format/3 as format(string(String), ...)
  191:- module_transparent sformat/2, sformat/3.  192
  193sformat(String, Format) :-
  194    format(string(String), Format, []).
  195sformat(String, Format, Arguments) :-
  196    format(string(String), Format, Arguments).
 concat(+Atom1, +Atom2, -Atom) is det
deprecated
- Use ISO atom_concat/3
  202concat(A, B, C) :-
  203    atom_concat(A, B, C).
 concat_atom(+List, -Atom) is det
Concatenate a list of atomic values to an atom.
deprecated
- Use atomic_list_concat/2 as proposed by the prolog commons initiative.
  212concat_atom([A, B], C) :-
  213    !,
  214    atom_concat(A, B, C).
  215concat_atom(L, Atom) :-
  216    atomic_list_concat(L, Atom).
 concat_atom(+List, +Separator, -Atom) is det
Concatenate a list of atomic values to an atom, inserting Separator between each consecutive elements.
deprecated
- Use atomic_list_concat/3 as proposed by the prolog commons initiative.
  227concat_atom(L, Sep, Atom) :-
  228    atomic_list_concat(L, Sep, Atom).
 $apropos_match(+Needle, +Haystack) is semidet
True if Needle is a sub atom of Haystack. Ignores the case of Haystack.
  235'$apropos_match'(Needle, Haystack) :-
  236    sub_atom_icasechk(Haystack, _, Needle).
 read_clause(-Term) is det
deprecated
- Use read_clause/3 or read_term/3.
  242read_clause(Term) :-
  243    read_clause(current_input, Term).
 read_clause(+Stream, -Term) is det
deprecated
- Use read_clause/3 or read_term/3.
  249read_clause(Stream, Term) :-
  250    read_clause(Stream, Term, [process_comment(false)]).
 read_variables(-Term, -Bindings) is det
 read_variables(+In:stream, -Term, -Bindings) is det
deprecated
- Use ISO read_term/2 or read_term/3.
  257read_variables(Term, Vars) :-
  258    read_term(Term, [variable_names(Vars)]).
  259
  260read_variables(Stream, Term, Vars) :-
  261    read_term(Stream, Term, [variable_names(Vars)]).
 read_pending_input(+Stream, -Codes, ?Tail) is det
deprecated
- Use read_pending_codes/3.
  267read_pending_input(Stream, Codes, Tail) :-
  268    read_pending_codes(Stream, Codes, Tail).
 feature(?Key, ?Value) is nondet
 set_feature(+Key, @Term) is det
Control Prolog flags.
deprecated
- Use ISO current_prolog_flag/2 and set_prolog_flag/2.
  277feature(Key, Value) :-
  278    current_prolog_flag(Key, Value).
  279
  280set_feature(Key, Value) :-
  281    set_prolog_flag(Key, Value).
 substring(+String, +Offset, +Length, -Sub)
Predecessor of sub_string using 1-based Offset.
deprecated
- Use sub_string/5.
  289substring(String, Offset, Length, Sub) :-
  290    Offset0 is Offset - 1,
  291    sub_string(String, Offset0, Length, _After, Sub).
 string_to_list(?String, ?Codes) is det
Bi-directional conversion between a string and a list of character codes.
deprecated
- Use string_codes/2.
  300string_to_list(String, Codes) :-
  301    string_codes(String, Codes).
 string_to_atom(?String, ?Atom) is det
Bi-directional conversion between string and atom.
deprecated
- Use atom_string/2. Note that the order of the arguments is reversed.
  310string_to_atom(Atom, String) :-
  311    atom_string(String, Atom).
 flush is det
deprecated
- use ISO flush_output/0.
  317flush :-
  318    flush_output.
 write_ln(X) is det
deprecated
- Use writeln(X).
  324write_ln(X) :-
  325    writeln(X).
 proper_list(+List)
Old SWI-Prolog predicate to check for a list that really ends in a []. There is not much use for the quick is_list, as in most cases you want to process the list element-by-element anyway.
deprecated
- Use ISO is_list/1.
  335proper_list(List) :-
  336    is_list(List).
 free_variables(+Term, -Variables)
Return a list of unbound variables in Term. The name term_variables/2 is more widely used.
deprecated
- Use term_variables/2.
  345free_variables(Term, Variables) :-
  346    term_variables(Term, Variables).
 hash_term(+Term, -Hash) is det
If Term is ground, Hash is unified to an integer representing a hash for Term. Otherwise Hash is left unbound.
deprecated
- Use term_hash/2.
  355hash_term(Term, Hash) :-
  356    term_hash(Term, Hash).
 checklist(:Goal, +List)
deprecated
- Use maplist/2
  363checklist(Goal, List) :-
  364    maplist(Goal, List).
 sublist(:Goal, +List1, ?List2)
Succeeds if List2 unifies with a list holding those terms for wich call(Goal, Elem) succeeds.
deprecated
- Use include/3 from library(apply)
Compatibility
- DEC10 library
  374sublist(_, [], []) :- !.
  375sublist(Goal, [H|T], Sub) :-
  376    call(Goal, H),
  377    !,
  378    Sub = [H|R],
  379    sublist(Goal, T, R).
  380sublist(Goal, [_|T], R) :-
  381    sublist(Goal, T, R).
 sumlist(+List, -Sum) is det
True when Sum is the list of all numbers in List.
deprecated
- Use sum_list/2
  389sumlist(List, Sum) :-
  390    sum_list(List, Sum).
 $strip_module(+Term, -Module, -Plain)
This used to be an internal predicate. It was added to the XPCE compatibility library without $ and since then used at many places. From 5.4.1 onwards strip_module/3 is built-in and the $ variation is added here for compatibility.
deprecated
- Use strip_module/3.
  401:- module_transparent
  402    '$strip_module'/3.  403
  404'$strip_module'(Term, Module, Plain) :-
  405    strip_module(Term, Module, Plain).
 $module(-OldTypeIn, +NewTypeIn)
  409'$module'(OldTypeIn, NewTypeIn) :-
  410    '$current_typein_module'(OldTypeIn),
  411    '$set_typein_module'(NewTypeIn).
 $declare_module(Module, File, Line)
Used in triple20 particle library. Should use a public interface
  417'$declare_module'(Module, File, Line) :-
  418    '$declare_module'(Module, user, user, File, Line, false).
 at_initialization(:Goal) is det
Register goal only to be run if a saved state is restored.
deprecated
- Use initialization(Goal, restore)
  427at_initialization(Goal) :-
  428    initialization(Goal, restore).
 convert_time(+Stamp, -String)
Convert a time-stamp as obtained though get_time/1 into a textual representation using the C-library function ctime(). The value is returned as a SWI-Prolog string object (see section 4.23). See also convert_time/8.
deprecated
- Use format_time/3.
  440convert_time(Stamp, String) :-
  441    format_time(string(String), '%+', Stamp).
 convert_time(+Stamp, -Y, -Mon, -Day, -Hour, -Min, -Sec, -MilliSec)
Convert a time stamp, provided by get_time/1, time_file/2, etc. Year is unified with the year, Month with the month number (January is 1), Day with the day of the month (starting with 1), Hour with the hour of the day (0--23), Minute with the minute (0--59). Second with the second (0--59) and MilliSecond with the milliseconds (0--999). Note that the latter might not be accurate or might always be 0, depending on the timing capabilities of the system. See also convert_time/2.
deprecated
- Use stamp_date_time/3.
  456convert_time(Stamp, Y, Mon, Day, Hour, Min, Sec, MilliSec) :-
  457    stamp_date_time(Stamp,
  458                    date(Y, Mon, Day,
  459                         Hour, Min, FSec,
  460                         _, _, _),
  461                    local),
  462    Sec is integer(float_integer_part(FSec)),
  463    MilliSec is integer(float_fractional_part(FSec)*1000).
 C(?List, ?Head, ?Tail) is det
Used to be generated by DCG. Some people appear to be using in in normal code too.
deprecated
- Do not use in normal code; DCG no longer generates it.
  472'C'([H|T], H, T).
 current_thread(?Thread, ?Status) is nondet
deprecated
- Replaced by thread_property/2
  479current_thread(Thread, Status) :-
  480    nonvar(Thread),
  481    !,
  482    catch(thread_property(Thread, status(Status)),
  483          error(existence_error(thread, _), _),
  484          fail).
  485current_thread(Thread, Status) :-
  486    thread_property(Thread, status(Status)).
 current_mutex(?Mutex, ?Owner, ?Count) is nondet
deprecated
- Replaced by mutex_property/2
  492current_mutex(Mutex, Owner, Count) :-
  493    nonvar(Mutex),
  494    !,
  495    catch(mutex_property(Mutex, status(Status)),
  496          error(existence_error(mutex, _), _),
  497          fail),
  498    map_mutex_status(Status, Owner, Count).
  499current_mutex(Mutex, Owner, Count) :-
  500    mutex_property(Mutex, status(Status)),
  501    map_mutex_status(Status, Owner, Count).
  502
  503map_mutex_status(unlocked, [], 0).
  504map_mutex_status(locked(Owner, Count), Owner, Count).
 message_queue_size(+Queue, -Size) is det
True if Queue holds Size terms.
deprecated
- Please use message_queue_property(Queue, Size)
  513message_queue_size(Queue, Size) :-
  514    message_queue_property(Queue, size(Size)).
 lock_predicate(+Name, +Arity) is det
 unlock_predicate(+Name, +Arity) is det
deprecated
- see lock_predicate/1 and unlock_predicate/1.
  521:- module_transparent
  522    lock_predicate/2,
  523    unlock_predicate/2.  524
  525lock_predicate(Name, Arity) :-
  526    lock_predicate(Name/Arity).
  527
  528unlock_predicate(Name, Arity) :-
  529    unlock_predicate(Name/Arity).
 current_module(?Module, ?File) is nondet
True if Module is a module loaded from File.
deprecated
- Use module_property(Module, file(File))
  537current_module(Module, File) :-
  538    module_property(Module, file(File)).
 export_list(+Module, -List) is det
Module exports the predicates of List.
deprecated
- Use module_property(Module, exports(List))
  546export_list(Module, List) :-
  547    module_property(Module, exports(List)).
 setup_and_call_cleanup(:Setup, :Goal, :Cleanup)
Call Cleanup once after Goal is finished.
deprecated
- Use setup_call_cleanup/3.
  555setup_and_call_cleanup(Setup, Goal, Cleanup) :-
  556    setup_call_cleanup(Setup, Goal, Cleanup).
 setup_and_call_cleanup(:Setup, :Goal, Catcher, :Cleanup)
Call Cleanup once after Goal is finished, with Catcher unified to the reason
deprecated
- Use setup_call_cleanup/3.
  565setup_and_call_cleanup(Setup, Goal, Catcher, Cleanup) :-
  566    setup_call_catcher_cleanup(Setup, Goal, Catcher,Cleanup).
 merge_set(+Set1, +Set2, -Set3)
Merge the ordered sets Set1 and Set2 into a new ordered set without duplicates.
deprecated
- New code should use ord_union/3 from library(ordsets)
  576merge_set([], L, L) :- !.
  577merge_set(L, [], L) :- !.
  578merge_set([H1|T1], [H2|T2], [H1|R]) :- H1 @< H2, !, merge_set(T1, [H2|T2], R).
  579merge_set([H1|T1], [H2|T2], [H2|R]) :- H1 @> H2, !, merge_set([H1|T1], T2, R).
  580merge_set([H1|T1], [H2|T2], [H1|R]) :- H1 == H2,    merge_set(T1, T2, R).
 merge(+List1, +List2, -List3)
Merge the ordered sets List1 and List2 into a new ordered list. Duplicates are not removed and their order is maintained.
deprecated
- The name of this predicate is far too general for a rather specific function.
  591merge([], L, L) :- !.
  592merge(L, [], L) :- !.
  593merge([H1|T1], [H2|T2], [H|R]) :-
  594    (   H1 @=< H2
  595    ->  H = H1,
  596        merge(T1, [H2|T2], R)
  597    ;   H = H2,
  598        merge([H1|T1], T2, R)
  599    ).
 index(:Head) is det
Prepare the predicate indicated by Head for multi-argument indexing.
deprecated
- As of version 5.11.29, SWI-Prolog performs just-in-time indexing on all arguments.
  609index(Head) :-
  610    print_message(warning, decl_no_effect(index(Head))).
 hash(:PredInd) is det
Demands PredInd to be indexed using a hash-table. This is handled dynamically.
  617hash(PI) :-
  618    print_message(warning, decl_no_effect(hash(PI))).
 set_base_module(:Base) is det
Set the default module from whic we inherit.
deprecated
- Equivalent to set_module(base(Base)).
  626set_base_module(M:Base) :-
  627    set_module(M:base(Base)).
 eval_license is det
deprecated
- Equivalent to license/0
  633eval_license :-
  634    license.
 trie_insert_new(+Trie, +Term, -Handle) is semidet
deprecated
- use trie_insert/4.
  640trie_insert_new(Trie, Term, Handle) :-
  641    trie_insert(Trie, Term, [], Handle).
 thread_at_exit(:Goal) is det
Register Goal to be called when the calling thread exits. @deprecated use prolog_listen(this_thread_exit, Goal)
  648thread_at_exit(Goal) :-
  649    prolog_listen(this_thread_exit, Goal)