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)  1985-2020, University of Amsterdam
    7                              VU University Amsterdam
    8                              CWI Amsterdam
    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('$history',
   38          [ read_term_with_history/2,           % -Term, +Line
   39            '$save_history_line'/1,             % +Line
   40            '$clean_history'/0,
   41            '$load_history'/0,
   42            '$save_history_event'/1
   43          ]).   44
   45%!  read_term_with_history(-Term, +Options)
   46%
   47%   Read a term guide by Options and  maintain a history similar to most
   48%   Unix shells.
   49%
   50%   When read_history reads a term of   the  form $silent(Goal), it will
   51%   call Goal and pretend it has not seen anything. This hook is used by
   52%   the GNU-Emacs interface to for   communication between GNU-EMACS and
   53%   SWI-Prolog.
   54
   55read_term_with_history(Term, Options) :-
   56    '$option'(prompt(Prompt), Options, '~! ?-'),
   57    '$option'(input(Input), Options, user_input),
   58    repeat,
   59        prompt_history(Prompt),
   60        '$toplevel':read_query_line(Input, Raw),
   61        read_history_(Raw, Term, Options),
   62    !.
   63
   64read_history_(Raw, _Term, Options) :-
   65    '$option'(show(Raw), Options, history),
   66    list_history,
   67    !,
   68    fail.
   69read_history_(Raw, _Term, Options) :-
   70    '$option'(help(Raw), Options, '!help'),
   71    '$option'(show(Show), Options, '!history'),
   72    print_message(help, history(help(Show, Raw))),
   73    !,
   74    fail.
   75read_history_(Raw, Term, Options) :-
   76    expand_history(Raw, Expanded, Changed),
   77    '$save_history_line'(Expanded),
   78    '$option'(module(Module), Options, Var),
   79    (   Module == Var
   80    ->  '$current_typein_module'(Module)
   81    ;   true
   82    ),
   83    (   '$select'(variable_names(Bindings), Options, Options1)
   84    ->  true
   85    ;   Options1 = Options,
   86        i(Bindings)                     % ignore
   87    ),
   88    catch(read_term_from_atom(Expanded, Term0,
   89                              [ module(Module),
   90                                variable_names(Bindings0)
   91                              | Options1
   92                              ]),
   93          E,
   94          (   print_message(error, E),
   95              fail
   96          )),
   97    (   var(Term0)
   98    ->  Term = Term0,
   99        Bindings = Bindings0
  100    ;   Term0 = '$silent'(Goal)
  101    ->  user:ignore(Goal),
  102        read_term_with_history(Term, Options)
  103    ;   save_event(Expanded, Options),
  104        (   Changed == true
  105        ->  print_message(query, history(expanded(Expanded)))
  106        ;   true
  107        ),
  108        Term = Term0,
  109        Bindings = Bindings0
  110    ).
  111
  112i(_).
  113
  114%   list_history
  115%   Write history events to the current output stream.
  116
  117list_history :-
  118    (   '$history'(Last, _)
  119    ->  true
  120    ;   Last = 0
  121    ),
  122    history_depth_(Depth),
  123    plus(First, Depth, Last),
  124    findall(Nr/Event,
  125            (   between(First, Last, Nr),
  126                '$history'(Nr, Event)
  127            ),
  128            Events),
  129    print_message(query, history(history(Events))).
  130
  131'$clean_history' :-
  132    retractall('$history'(_,_)).
  133
  134%!  '$load_history' is det.
  135%
  136%   Load persistent history using a hook
  137
  138'$load_history' :-
  139    '$clean_history',
  140    current_prolog_flag(history, Depth),
  141    Depth > 0,
  142    catch(prolog:history(current_input, load), _, true), !.
  143'$load_history'.
  144
  145
  146%%   prompt_history(+Prompt)
  147%
  148%    Give prompt, substituting '~!' by the event number.
  149
  150prompt_history('') :-
  151    !,
  152    ttyflush.
  153prompt_history(Prompt) :-
  154    (   '$history'(Last, _)
  155    ->  This is Last + 1
  156    ;   This = 1
  157    ),
  158    atom_codes(Prompt, SP),
  159    atom_codes(This, ST),
  160    (   atom_codes('~!', Repl),
  161        substitute(Repl, ST, SP, String)
  162    ->  prompt1(String)
  163    ;   prompt1(Prompt)
  164    ),
  165    ttyflush.
  166
  167%   substitute(+Old, +New, +String, -Substituted)
  168%   substitute first occurence of Old in String by New
  169
  170substitute(Old, New, String, Substituted) :-
  171    '$append'(Head, OldAndTail, String),
  172    '$append'(Old, Tail, OldAndTail),
  173    !,
  174    '$append'(Head, New, HeadAndNew),
  175    '$append'(HeadAndNew, Tail, Substituted),
  176    !.
  177
  178%!  '$save_history_line'(+Line)
  179%
  180%   Add Line to the command line editing history.
  181
  182:- multifile
  183    prolog:history_line/2.  184
  185'$save_history_line'(end_of_file) :- !.
  186'$save_history_line'(Line) :-
  187    format(string(CompleteLine), '~W~W',
  188           [ Line, [partial(true)],
  189             '.',  [partial(true)]
  190           ]),
  191    catch(prolog:history(user_input, add(CompleteLine)), _, fail),
  192    !.
  193'$save_history_line'(_).
  194
  195%!  save_event(+Event, +Options)
  196%
  197%   Save Event into the  history  system unless it appears in the
  198%   option `no_save`.
  199
  200save_event(Event, Options) :-
  201    '$option'(no_save(Dont), Options),
  202    memberchk(Event, Dont),
  203    !.
  204save_event(Event, _) :-
  205    '$save_history_event'(Event).
  206
  207%!  '$save_history_event'(+Event) is det.
  208%
  209%   Save an input line as text into the !- based history. Event is one
  210%   of
  211%
  212%     * a *string*.  The event is added with a next number at the end.
  213%     * a *pair*.  The event is added with the given sequence number.
  214
  215:- thread_local
  216    '$history'/2.  217
  218'$save_history_event'(Num-String) :-
  219    integer(Num), string(String),
  220    !,
  221    asserta('$history'(Num, String)),
  222    truncate_history(Num).
  223'$save_history_event'(Event) :-
  224    to_string(Event, Event1),
  225    !,
  226    last_event(Num, String),
  227    (   Event1 == String
  228    ->  true
  229    ;   New is Num + 1,
  230        asserta('$history'(New, Event1)),
  231        truncate_history(New)
  232    ).
  233'$save_history_event'(Event) :-
  234    '$type_error'(history_event, Event).
  235
  236last_event(Num, String) :-
  237    '$history'(Num, String),
  238    !.
  239last_event(0, "").
  240
  241to_string(String, String) :-
  242    string(String),
  243    !.
  244to_string(Atom, String) :-
  245    atom_string(Atom, String).
  246
  247truncate_history(New) :-
  248    history_depth_(Depth),
  249    remove_history(New, Depth).
  250
  251remove_history(New, Depth) :-
  252    New - Depth =< 0,
  253    !.
  254remove_history(New, Depth) :-
  255    Remove is New - Depth,
  256    retract('$history'(Remove, _)),
  257    !.
  258remove_history(_, _).
  259
  260%    history_depth_(-Depth)
  261%    Define the depth to which to keep the history.
  262
  263history_depth_(N) :-
  264    current_prolog_flag(history, N),
  265    integer(N),
  266    N > 0,
  267    !.
  268history_depth_(25).
  269
  270%    expand_history(+Raw, -Expanded)
  271%    Expand Raw using the available history list. Expandations performed
  272%    are:
  273%
  274%       !match          % Last event starting <match>
  275%       !n              % Event nr. <n>
  276%       !!              % last event
  277%
  278%    Note: the first character after a '!' should be a letter or number to
  279%    avoid problems with the cut.
  280
  281expand_history(Raw, Expanded, Changed) :-
  282    atom_chars(Raw, RawString),
  283    expand_history2(RawString, ExpandedString, Changed),
  284    atom_chars(Expanded, ExpandedString),
  285    !.
  286
  287expand_history2([!], [!], false) :- !.
  288expand_history2([!, C|Rest], [!|Expanded], Changed) :-
  289    not_event_char(C),
  290    !,
  291    expand_history2([C|Rest], Expanded, Changed).
  292expand_history2([!|Rest], Expanded, true) :-
  293    !,
  294    match_event(Rest, Event, NewRest),
  295    '$append'(Event, RestExpanded, Expanded),
  296    !,
  297    expand_history2(NewRest, RestExpanded, _).
  298expand_history2(['\''|In], ['\''|Out], Changed) :-
  299    !,
  300    skip_quoted(In, '\'', Out, Tin, Tout),
  301    expand_history2(Tin, Tout, Changed).
  302expand_history2(['"'|In], ['"'|Out], Changed) :-
  303    !,
  304    skip_quoted(In, '"', Out, Tin, Tout),
  305    expand_history2(Tin, Tout, Changed).
  306expand_history2([H|T], [H|R], Changed) :-
  307    !,
  308    expand_history2(T, R, Changed).
  309expand_history2([], [], false).
  310
  311skip_quoted([Q|T],Q,[Q|R], T, R) :- !.
  312skip_quoted([\,Q|T0],Q,[\,Q|T], In, Out) :-
  313    !,
  314    skip_quoted(T0, Q, T, In, Out).
  315skip_quoted([Q,Q|T0],Q,[Q,Q|T], In, Out) :-
  316    !,
  317    skip_quoted(T0, Q, T, In, Out).
  318skip_quoted([C|T0],Q,[C|T], In, Out) :-
  319    !,
  320    skip_quoted(T0, Q, T, In, Out).
  321skip_quoted([], _, [], [], []).
  322
  323%   get_last_event(-String)
  324%   return last event typed as a string
  325
  326get_last_event(Event) :-
  327    '$history'(_, Atom),
  328    atom_chars(Atom, Event),
  329    !.
  330get_last_event(_) :-
  331    print_message(query, history(no_event)),
  332    fail.
  333
  334%   match_event(+Spec, -Event, -Rest)
  335%   Use Spec as a specification of and event and return the event as Event
  336%   and what is left of Spec as Rest.
  337
  338match_event(Spec, Event, Rest) :-
  339    find_event(Spec, Event, Rest),
  340    !.
  341match_event(_, _, _) :-
  342    print_message(query, history(no_event)),
  343    fail.
  344
  345not_event_char(C) :- code_type(C, csym), !, fail.
  346not_event_char(!) :- !, fail.
  347not_event_char(_).
  348
  349find_event([!|Left], Event, Left) :-
  350    !,
  351    get_last_event(Event).
  352find_event([N|Rest], Event, Left) :-
  353    code_type(N, digit),
  354    !,
  355    take_number([N|Rest], String, Left),
  356    number_codes(Number, String),
  357    '$history'(Number, Atom),
  358    atom_chars(Atom, Event).
  359find_event(Spec, Event, Left) :-
  360    take_string(Spec, String, Left),
  361    matching_event(String, Event).
  362
  363take_string([C|Rest], [C|String], Left) :-
  364    code_type(C, csym),
  365    !,
  366    take_string(Rest, String, Left).
  367take_string([C|Rest], [], [C|Rest]) :- !.
  368take_string([], [], []).
  369
  370take_number([C|Rest], [C|String], Left) :-
  371    code_type(C, digit),
  372    !,
  373    take_string(Rest, String, Left).
  374take_number([C|Rest], [], [C|Rest]) :- !.
  375take_number([], [], []).
  376
  377%   matching_event(+String, -Event)
  378%
  379%   Return first event with prefix String as a Prolog string.
  380
  381matching_event(String, Event) :-
  382    '$history'(_, AtomEvent),
  383    atom_chars(AtomEvent, Event),
  384    '$append'(String, _, Event),
  385    !