1/*  Part of SWI-Prolog
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           www.swi-prolog.org
    6    Copyright (c)  2013-2015, 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('$dicts',
   37          [ '.'/3                               % +Left, +Right, -Result
   38          ]).

 .(+R, +L, -Result)

Evaluate dot expressions. Note that '$get_dict_ex' fails if the first argument is not a dict or the second is not a valid key or unbound.

   46.(Data, Func, Value) :-
   47    (   '$get_dict_ex'(Func, Data, V0)
   48    *-> Value = V0
   49    ;   is_dict(Data, Tag)
   50    ->  eval_dict_function(Func, Tag, Data, Value)
   51    ;   is_list(Data)
   52    ->  (   (atomic(Func) ; var(Func))
   53        ->  dict_create(Dict, _, Data),
   54            '$get_dict_ex'(Func, Dict, Value)
   55        ;   '$type_error'(atom, Func)
   56        )
   57    ;   '$type_error'(dict, Data)
   58    ).

 eval_dict_function(+Func, +Tag, +Dict, -Value)

Test for predefined functions on dicts or evaluate a user-defined function.

   66eval_dict_function(get(Key), _, Dict, Value) :-
   67    !,
   68    get_dict(Key, Dict, Value).
   69eval_dict_function(put(Key, Value), _, Dict, NewDict) :-
   70    !,
   71    (   atomic(Key)
   72    ->  put_dict(Key, Dict, Value, NewDict)
   73    ;   put_dict_path(Key, Dict, Value, NewDict)
   74    ).
   75eval_dict_function(put(New), _, Dict, NewDict) :-
   76    !,
   77    put_dict(New, Dict, NewDict).
   78eval_dict_function(Func, Tag, Dict, Value) :-
   79    call(Tag:Func, Dict, Value).

 put_dict_path(+KeyPath, +Dict, +Value, -NewDict)

Add/replace a value according to a path definition. Path segments are separated using '/'.

   87put_dict_path(Key, Dict, Value, NewDict) :-
   88    atom(Key),
   89    !,
   90    put_dict(Key, Dict, Value, NewDict).
   91put_dict_path(Path, Dict, Value, NewDict) :-
   92    get_dict_path(Path, Dict, _Old, NewDict, Value).
   93
   94get_dict_path(Path, _, _, _, _) :-
   95    var(Path),
   96    !,
   97    '$instantiation_error'(Path).
   98get_dict_path(Path/Key, Dict, Old, NewDict, New) :-
   99    !,
  100    get_dict_path(Path, Dict, OldD, NewDict, NewD),
  101    (   get_dict(Key, OldD, Old, NewD, New),
  102        is_dict(Old)
  103    ->  true
  104    ;   Old = _{},
  105        put_dict(Key, OldD, New, NewD)
  106    ).
  107get_dict_path(Key, Dict, Old, NewDict, New) :-
  108    get_dict(Key, Dict, Old, NewDict, New),
  109    is_dict(Old),
  110    !.
  111get_dict_path(Key, Dict, _{}, NewDict, New) :-
  112    put_dict(Key, Dict, New, NewDict).
  113
  114
  115                 /*******************************
  116                 *             REGISTER         *
  117                 *******************************/

 system:term_expansion(+TermIn, -TermOut)

Support := syntax for defining new functions.

To be done

- Modify to term_expansion/4, including position management

  126% note that we need FHead because using a term there rewrites the
  127% clauses using function expansion.
  128
  129expand_dict_function((QFHead := V0 :- Body), (QHead :- Body, Eval)) :-
  130    fqhead(QFHead, FHead, Head, QHead),
  131    compound(FHead),
  132    FHead =.. [.,R,M],
  133    callable(M),
  134    !,
  135    '$expand':replace_functions(V0, Eval, V, _Ctx),
  136    compound_name_arguments(M, Name, Args0),
  137    '$append'(Args0, [R,V], Args),
  138    compound_name_arguments(Head, Name, Args).
  139expand_dict_function((QFHead := V0), (QHead :- Eval)) :-
  140    fqhead(QFHead, FHead, Head, QHead),
  141    compound(FHead),
  142    FHead =.. [.,R,M],
  143    callable(M),
  144    !,
  145    '$expand':replace_functions(V0, Eval, V, _Ctx),
  146    compound_name_arguments(M, Name, Args0),
  147    '$append'(Args0, [R,V], Args),
  148    compound_name_arguments(Head, Name, Args).
  149
  150fqhead(M:FHead, FHead, Head, M:Head) :- !.
  151fqhead(FHead,   FHead, Head,   Head).
  152
  153
  154system:term_expansion(FDecl, Clause) :-
  155    expand_dict_function(FDecl, Clause).
  156system:term_expansion(M:FDecl, QClause) :-
  157    expand_dict_function(FDecl, Clause),
  158    !,
  159    QClause = M:Clause