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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)  2007-2023, University of Amsterdam
    7                              VU University Amsterdam
    8                              SWI-Prolog Solutions b.v.
    9    All rights reserved.
   10
   11    Redistribution and use in source and binary forms, with or without
   12    modification, are permitted provided that the following conditions
   13    are met:
   14
   15    1. Redistributions of source code must retain the above copyright
   16       notice, this list of conditions and the following disclaimer.
   17
   18    2. Redistributions in binary form must reproduce the above copyright
   19       notice, this list of conditions and the following disclaimer in
   20       the documentation and/or other materials provided with the
   21       distribution.
   22
   23    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   24    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   25    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   26    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   27    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   28    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   29    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   30    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   31    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   32    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   33    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   34    POSSIBILITY OF SUCH DAMAGE.
   35*/
   36
   37:- module(apply,
   38          [ include/3,                  % :Pred, +List, -Ok
   39            exclude/3,                  % :Pred. +List, -NotOk
   40            partition/4,                % :Pred, +List, -Included, -Excluded
   41            partition/5,                % :Pred, +List, ?Less, ?Equal, ?Greater
   42            maplist/2,                  % :Pred, +List
   43            maplist/3,                  % :Pred, ?List, ?List
   44            maplist/4,                  % :Pred, ?List, ?List, ?List
   45            maplist/5,                  % :Pred, ?List, ?List, ?List, ?List
   46            convlist/3,                 % :Pred, +List, -List
   47            foldl/4,                    % :Pred, +List, ?V0, ?V
   48            foldl/5,                    % :Pred, +List1, +List2, ?V0, ?V
   49            foldl/6,                    % :Pred, +List1, +List2, +List3, ?V0, ?V
   50            foldl/7,                    % :Pred, +List1, +List2, +List3, +List4,
   51                                        % ?V0, ?V
   52            scanl/4,                    % :Pred, +List, ?V0, ?Vs
   53            scanl/5,                    % :Pred, +List1, +List2, ?V0, ?Vs
   54            scanl/6,                    % :Pred, +List1, +List2, +List3, ?V0, ?Vs
   55            scanl/7                     % :Pred, +List1, +List2, +List3, +List4,
   56                                        % ?V0, ?Vs
   57          ]).   58:- autoload(library(error),[must_be/2]).   59:- set_prolog_flag(generate_debug_info, false).   60
   61/** <module> Apply predicates on a list
   62
   63This module defines meta-predicates  that  apply   a  predicate  on  all
   64members of a list.
   65
   66All predicates support partial application in the  Goal  argument.  This
   67means that these calls are identical:
   68
   69```
   70?- maplist(=, [foo, foo], [X, Y]).
   71?- maplist(=(foo), [X, Y]).
   72```
   73
   74@see    apply_macros.pl provides compile-time expansion for part of this
   75        library.
   76@see    http://www.cs.otago.ac.nz/staffpriv/ok/pllib.htm
   77@see    Unit test code in src/Tests/library/test_apply.pl
   78@tbd    Add include/4, include/5, exclude/4, exclude/5
   79*/
   80
   81:- meta_predicate
   82    include(1, +, -),
   83    exclude(1, +, -),
   84    partition(1, +, -, -),
   85    partition(2, +, -, -, -),
   86    maplist(1, ?),
   87    maplist(2, ?, ?),
   88    maplist(3, ?, ?, ?),
   89    maplist(4, ?, ?, ?, ?),
   90    convlist(2, +, -),
   91    foldl(3, +, +, -),
   92    foldl(4, +, +, +, -),
   93    foldl(5, +, +, +, +, -),
   94    foldl(6, +, +, +, +, +, -),
   95    scanl(3, +, +, -),
   96    scanl(4, +, +, +, -),
   97    scanl(5, +, +, +, +, -),
   98    scanl(6, +, +, +, +, +, -).   99
  100
  101%!  include(:Goal, +List1, ?List2) is det.
  102%
  103%   Filter elements for which Goal  succeeds.   True  if  List2 contains
  104%   those elements Xi of List1 for which call(Goal, Xi) succeeds.
  105%
  106%   @see exclude/3, partition/4, convlist/3.
  107%   @compat Older versions of SWI-Prolog had sublist/3 with the same
  108%   arguments and semantics.
  109
  110include(Goal, List, Included) :-
  111    include_(List, Goal, Included).
  112
  113include_([], _, []).
  114include_([X1|Xs1], P, Included) :-
  115    (   call(P, X1)
  116    ->  Included = [X1|Included1]
  117    ;   Included = Included1
  118    ),
  119    include_(Xs1, P, Included1).
  120
  121
  122%!  exclude(:Goal, +List1, ?List2) is det.
  123%
  124%   Filter elements for which Goal fails.   True if List2 contains those
  125%   elements Xi of List1 for which call(Goal, Xi) fails.
  126%
  127%   @see include/3, partition/4
  128
  129exclude(Goal, List, Included) :-
  130    exclude_(List, Goal, Included).
  131
  132exclude_([], _, []).
  133exclude_([X1|Xs1], P, Included) :-
  134    (   call(P, X1)
  135    ->  Included = Included1
  136    ;   Included = [X1|Included1]
  137    ),
  138    exclude_(Xs1, P, Included1).
  139
  140
  141%!  partition(:Pred, +List, ?Included, ?Excluded) is det.
  142%
  143%   Filter elements of List according  to   Pred.  True  if Included
  144%   contains all elements  for  which   call(Pred,  X)  succeeds and
  145%   Excluded contains the remaining elements.
  146%
  147%   @see include/3, exclude/3, partition/5.
  148
  149partition(Pred, List, Included, Excluded) :-
  150    partition_(List, Pred, Included, Excluded).
  151
  152partition_([], _, [], []).
  153partition_([H|T], Pred, Incl, Excl) :-
  154    (   call(Pred, H)
  155    ->  Incl = [H|I],
  156        partition_(T, Pred, I, Excl)
  157    ;   Excl = [H|E],
  158        partition_(T, Pred, Incl, E)
  159    ).
  160
  161
  162%!  partition(:Pred, +List, ?Less, ?Equal, ?Greater) is semidet.
  163%
  164%   Filter List according to Pred in three sets. For each element Xi
  165%   of List, its destination is determined by call(Pred, Xi, Place),
  166%   where Place must be unified to  one   of  =|<|=, =|=|= or =|>|=.
  167%   Pred must be deterministic.
  168%
  169%   @see partition/4
  170
  171partition(Pred, List, Less, Equal, Greater) :-
  172    partition_(List, Pred, Less, Equal, Greater).
  173
  174partition_([], _, [], [], []).
  175partition_([H|T], Pred, L, E, G) :-
  176    call(Pred, H, Diff),
  177    partition_(Diff, H, Pred, T, L, E, G).
  178
  179partition_(<, H, Pred, T, L, E, G) :-
  180    !,
  181    L = [H|Rest],
  182    partition_(T, Pred, Rest, E, G).
  183partition_(=, H, Pred, T, L, E, G) :-
  184    !,
  185    E = [H|Rest],
  186    partition_(T, Pred, L, Rest, G).
  187partition_(>, H, Pred, T, L, E, G) :-
  188    !,
  189    G = [H|Rest],
  190    partition_(T, Pred, L, E, Rest).
  191partition_(Diff, _, _, _, _, _, _) :-
  192    must_be(oneof([<,=,>]), Diff).
  193
  194
  195                 /*******************************
  196                 *            MAPLIST           *
  197                 *******************************/
  198
  199%!  maplist(:Goal, ?List1).
  200%!  maplist(:Goal, ?List1, ?List2).
  201%!  maplist(:Goal, ?List1, ?List2, ?List3).
  202%!  maplist(:Goal, ?List1, ?List2, ?List3, ?List4).
  203%
  204%   True if Goal is successfully applied on all matching elements of the
  205%   list. The maplist family of predicates is defined as:
  206%
  207%     ```
  208%     maplist(G, [X_11, ..., X_1n],
  209%                [X_21, ..., X_2n],
  210%                ...,
  211%                [X_m1, ..., X_mn]) :-
  212%        call(G, X_11, ..., X_m1),
  213%        call(G, X_12, ..., X_m2),
  214%        ...
  215%        call(G, X_1n, ..., X_mn).
  216%     ```
  217%
  218%   This family of predicates is deterministic iff Goal is deterministic
  219%   and List1 is a proper list, i.e., a list that ends in `[]`.
  220
  221maplist(Goal, List) :-
  222    maplist_(List, Goal).
  223
  224maplist_([], _).
  225maplist_([Elem|Tail], Goal) :-
  226    call(Goal, Elem),
  227    maplist_(Tail, Goal).
  228
  229maplist(Goal, List1, List2) :-
  230    maplist_(List1, List2, Goal).
  231
  232maplist_([], [], _).
  233maplist_([Elem1|Tail1], [Elem2|Tail2], Goal) :-
  234    call(Goal, Elem1, Elem2),
  235    maplist_(Tail1, Tail2, Goal).
  236
  237maplist(Goal, List1, List2, List3) :-
  238    maplist_(List1, List2, List3, Goal).
  239
  240maplist_([], [], [], _).
  241maplist_([Elem1|Tail1], [Elem2|Tail2], [Elem3|Tail3], Goal) :-
  242    call(Goal, Elem1, Elem2, Elem3),
  243    maplist_(Tail1, Tail2, Tail3, Goal).
  244
  245maplist(Goal, List1, List2, List3, List4) :-
  246    maplist_(List1, List2, List3, List4, Goal).
  247
  248maplist_([], [], [], [], _).
  249maplist_([Elem1|Tail1], [Elem2|Tail2], [Elem3|Tail3], [Elem4|Tail4], Goal) :-
  250    call(Goal, Elem1, Elem2, Elem3, Elem4),
  251    maplist_(Tail1, Tail2, Tail3, Tail4, Goal).
  252
  253
  254%!  convlist(:Goal, +ListIn, -ListOut) is det.
  255%
  256%   Similar to maplist/3, but elements for   which call(Goal, ElemIn, _)
  257%   fails are omitted from ListOut.  For example (using library(yall)):
  258%
  259%   ```
  260%   ?- convlist([X,Y]>>(integer(X), Y is X^2),
  261%               [3, 5, foo, 2], L).
  262%   L = [9, 25, 4].
  263%   ```
  264%
  265%   @compat  Also  appears  in  YAP   =|library(maplist)|=  and  SICStus
  266%   =|library(lists)|=.
  267
  268convlist(Goal, ListIn, ListOut) :-
  269    convlist_(ListIn, ListOut, Goal).
  270
  271convlist_([], [], _).
  272convlist_([H0|T0], ListOut, Goal) :-
  273    (   call(Goal, H0, H)
  274    ->  ListOut = [H|T],
  275        convlist_(T0, T, Goal)
  276    ;   convlist_(T0, ListOut, Goal)
  277    ).
  278
  279
  280                 /*******************************
  281                 *            FOLDL             *
  282                 *******************************/
  283
  284%!  foldl(:Goal, +List, +V0, -V).
  285%!  foldl(:Goal, +List1, +List2, +V0, -V).
  286%!  foldl(:Goal, +List1, +List2, +List3, +V0, -V).
  287%!  foldl(:Goal, +List1, +List2, +List3, +List4, +V0, -V).
  288%
  289%   Fold an ensemble of _m_  (0  <=  _m_   <=  4)  lists  of  length _n_
  290%   head-to-tail ("fold-left"), using columns of   _m_  list elements as
  291%   arguments for Goal. The `foldl` family   of predicates is defined as
  292%   follows, with `V0` an initial value and   `V` the final value of the
  293%   folding operation:
  294%
  295%     ```
  296%     foldl(G, [X_11, ..., X_1n],
  297%              [X_21, ..., X_2n],
  298%              ...,
  299%              [X_m1, ..., X_mn], V0, V) :-
  300%        call(G, X_11, ..., X_m1, V0, V1),
  301%        call(G, X_12, ..., X_m2, V1, V2),
  302%        ...
  303%        call(G, X_1n, ..., X_mn, V<n-1>, V).
  304%     ```
  305%
  306%   No implementation for a corresponding `foldr`   is  given. A `foldr`
  307%   implementation would consist in first calling   reverse/2 on each of
  308%   the _m_ input lists, then applying  the appropriate `foldl`. This is
  309%   actually  more  efficient  than  using   a  properly  programmed-out
  310%   recursive algorithm that cannot be   tail-call optimized.
  311
  312foldl(Goal, List, V0, V) :-
  313    foldl_(List, Goal, V0, V).
  314
  315foldl_([], _, V, V).
  316foldl_([H|T], Goal, V0, V) :-
  317    call(Goal, H, V0, V1),
  318    foldl_(T, Goal, V1, V).
  319
  320
  321foldl(Goal, List1, List2, V0, V) :-
  322    foldl_(List1, List2, Goal, V0, V).
  323
  324foldl_([], [], _, V, V).
  325foldl_([H1|T1], [H2|T2], Goal, V0, V) :-
  326    call(Goal, H1, H2, V0, V1),
  327    foldl_(T1, T2, Goal, V1, V).
  328
  329
  330foldl(Goal, List1, List2, List3, V0, V) :-
  331    foldl_(List1, List2, List3, Goal, V0, V).
  332
  333foldl_([], [], [], _, V, V).
  334foldl_([H1|T1], [H2|T2], [H3|T3], Goal, V0, V) :-
  335    call(Goal, H1, H2, H3, V0, V1),
  336    foldl_(T1, T2, T3, Goal, V1, V).
  337
  338
  339foldl(Goal, List1, List2, List3, List4, V0, V) :-
  340    foldl_(List1, List2, List3, List4, Goal, V0, V).
  341
  342foldl_([], [], [], [], _, V, V).
  343foldl_([H1|T1], [H2|T2], [H3|T3], [H4|T4], Goal, V0, V) :-
  344    call(Goal, H1, H2, H3, H4, V0, V1),
  345    foldl_(T1, T2, T3, T4, Goal, V1, V).
  346
  347
  348                 /*******************************
  349                 *             SCANL            *
  350                 *******************************/
  351
  352%!  scanl(:Goal, +List, +V0, -Values).
  353%!  scanl(:Goal, +List1, +List2, +V0, -Values).
  354%!  scanl(:Goal, +List1, +List2, +List3, +V0, -Values).
  355%!  scanl(:Goal, +List1, +List2, +List3, +List4, +V0, -Values).
  356%
  357%   Scan an ensemble of _m_  (0  <=  _m_   <=  4)  lists  of  length _n_
  358%   head-to-tail ("scan-left"), using columns of   _m_  list elements as
  359%   arguments for Goal. The `scanl` family   of predicates is defined as
  360%   follows, with `V0` an initial value and   `V` the final value of the
  361%   scanning operation:
  362%
  363%     ```
  364%     scanl(G, [X_11, ..., X_1n],
  365%              [X_21, ..., X_2n],
  366%              ...,
  367%              [X_m1, ..., X_mn], V0, [V0, V1, ..., Vn] ) :-
  368%        call(G, X_11, ..., X_m1, V0, V1),
  369%        call(G, X_12, ..., X_m2, V1, V2),
  370%        ...
  371%        call(G, X_1n, ..., X_mn, V<n-1>, Vn).
  372%     ```
  373%
  374%  `scanl` behaves like a `foldl` that collects the sequence of
  375%  values taken on by the `Vx` accumulator into a list.
  376
  377scanl(Goal, List, V0, [V0|Values]) :-
  378    scanl_(List, Goal, V0, Values).
  379
  380scanl_([], _, _, []).
  381scanl_([H|T], Goal, V, [VH|VT]) :-
  382    call(Goal, H, V, VH),
  383    scanl_(T, Goal, VH, VT).
  384
  385
  386scanl(Goal, List1, List2, V0, [V0|Values]) :-
  387    scanl_(List1, List2, Goal, V0, Values).
  388
  389scanl_([], [], _, _, []).
  390scanl_([H1|T1], [H2|T2], Goal, V, [VH|VT]) :-
  391    call(Goal, H1, H2, V, VH),
  392    scanl_(T1, T2, Goal, VH, VT).
  393
  394
  395scanl(Goal, List1, List2, List3, V0, [V0|Values]) :-
  396    scanl_(List1, List2, List3, Goal, V0, Values).
  397
  398scanl_([], [], [], _, _, []).
  399scanl_([H1|T1], [H2|T2], [H3|T3], Goal, V, [VH|VT]) :-
  400    call(Goal, H1, H2, H3, V, VH),
  401    scanl_(T1, T2, T3, Goal, VH, VT).
  402
  403
  404scanl(Goal, List1, List2, List3, List4, V0, [V0|Values]) :-
  405    scanl_(List1, List2, List3, List4, Goal, V0, Values).
  406
  407scanl_([], [], [], [], _, _, []).
  408scanl_([H1|T1], [H2|T2], [H3|T3], [H4|T4], Goal, V, [VH|VT]) :-
  409    call(Goal, H1, H2, H3, H4, V, VH),
  410    scanl_(T1, T2, T3, T4, Goal, VH, VT).
  411
  412
  413                 /*******************************
  414                 *            SANDBOX           *
  415                 *******************************/
  416
  417:- multifile
  418    sandbox:safe_meta_predicate/1.  419
  420safe_api(Name/Arity, sandbox:safe_meta_predicate(apply:Name/Arity)).
  421
  422term_expansion(safe_api, Clauses) :-
  423    module_property(apply, exports(API)),
  424    maplist(safe_api, API, Clauses).
  425
  426safe_api