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)  1985-2015, 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(quintus,
   37        [ unix/1,
   38%         file_exists/1,
   39
   40          abs/2,
   41          sin/2,
   42          cos/2,
   43          tan/2,
   44          log/2,
   45          log10/2,
   46          pow/3,
   47          ceiling/2,
   48          floor/2,
   49          round/2,
   50          acos/2,
   51          asin/2,
   52          atan/2,
   53          atan2/3,
   54          sign/2,
   55          sqrt/2,
   56
   57          genarg/3,
   58
   59          (mode)/1,
   60          no_style_check/1,
   61          otherwise/0,
   62          simple/1,
   63%         statistics/2,                 % Please access as quintus:statistics/2
   64          prolog_flag/2,
   65
   66          date/1,                       % -date(Year, Month, Day)
   67
   68          current_stream/3,             % ?File, ?Mode, ?Stream
   69          stream_position/3,            % +Stream, -Old, +New
   70          skip_line/0,
   71          skip_line/1,                  % +Stream
   72
   73          compile/1,                    % +File(s)
   74
   75          atom_char/2,
   76          midstring/3,                  % ABC, B, AC
   77          midstring/4,                  % ABC, B, AC, LenA
   78          midstring/5,                  % ABC, B, AC, LenA, LenB
   79          midstring/6,                  % ABC, B, AC, LenA, LenB, LenC
   80
   81          raise_exception/1,            % +Exception
   82          on_exception/3                % +Ball, :Goal, :Recover
   83        ]).   84:- autoload(library(apply),[maplist/3]).   85:- autoload(library(date),[date_time_value/3]).   86:- autoload(library(shell),[shell/0]).

  105                /********************************
  106                *      SYSTEM INTERACTION       *
  107                *********************************/

 unix(+Action)

This predicate provides a partial emulation of the corresponding Quintus predicate. It provides access to some operating system features and unlike the name suggests, is not operating system specific. Defined actions are below.

system(+Command)

Equivalent to shell(Command)

shell(+Command)

Equivalent to shell(Command)

access(File, 0)

Equivalent to access_file(File, read)

cd(Dir)

Equivalent to working_directory(_, Dir)

args(List)

Equivalent to current_prolog_flag(os_argv, List).

argv(List)

Equivalent to args(List), but arguments that are syntactically valid numbers are passed as a number.

  130unix(system(Command)) :-
  131    shell(Command).
  132unix(shell(Command)) :-
  133    shell(Command).
  134unix(shell) :-
  135    shell.
  136unix(access(File, 0)) :-
  137    access_file(File, read).
  138unix(cd) :-
  139    expand_file_name(~, [Home]),
  140    working_directory(_, Home).
  141unix(cd(Dir)) :-
  142    working_directory(_, Dir).
  143unix(args(L)) :-
  144    current_prolog_flag(os_argv, L).
  145unix(argv(L)) :-
  146    current_prolog_flag(os_argv, S),
  147    maplist(to_prolog, S, L).
  148
  149to_prolog(S, A) :-
  150    name(S, L),
  151    name(A, L).
  152
  153
  154                /********************************
  155                *        META PREDICATES        *
  156                *********************************/

 otherwise

For (A -> B ; otherwise -> C)

  162otherwise.
  163
  164
  165                /********************************
  166                *          ARITHMETIC           *
  167                *********************************/

 abs(+Number, -Absolute)

Unify `Absolute' with the absolute value of `Number'.

  172abs(Number, Absolute) :-
  173    Absolute is abs(Number).

 sin(+Angle, -Sine) is det

 cos(+Angle, -Cosine) is det

 tan(+Angle, -Tangent) is det

 log(+X, -NatLog) is det

 log10(+X, -Log) is det

 pow(+X, +Y, -Pow) is det

 ceiling(+X, -Value) is det

 floor(+X, -Value) is det

 round(+X, -Value) is det

 sqrt(+X, -Value) is det

 acos(+X, -Value) is det

 asin(+X, -Value) is det

 atan(+X, -Value) is det

 atan2(+Y, +X, -Value) is det

 sign(+X, -Value) is det

Math library predicates. SWI-Prolog (and ISO) support these as functions under is/2, etc.

deprecated

- Do not use these predicates except for compatibility reasons.

Compatibility

- Quintus Prolog.

  198sin(A, V) :-      V is sin(A).
  199cos(A, V) :-      V is cos(A).
  200tan(A, V) :-      V is tan(A).
  201log(A, V) :-      V is log(A).
  202log10(X, V) :-    V is log10(X).
  203pow(X,Y,V) :-     V is X**Y.
  204ceiling(X, V) :-  V is ceil(X).
  205floor(X, V) :-    V is floor(X).
  206round(X, V) :-    V is round(X).
  207sqrt(X, V) :-     V is sqrt(X).
  208acos(X, V) :-     V is acos(X).
  209asin(X, V) :-     V is asin(X).
  210atan(X, V) :-     V is atan(X).
  211atan2(Y, X, V) :- V is atan(Y, X).
  212sign(X, V) :-     V is sign(X).
  213
  214
  215                 /*******************************
  216                 *      TERM MANIPULATION       *
  217                 *******************************/

 genarg(?Index, +Term, ?Arg) is nondet

Generalised version of ISO arg/3. SWI-Prolog's arg/3 is already genarg/3.

  224genarg(N, T, A) :-
  225    arg(N, T, A).
  226
  227
  228                 /*******************************
  229                 *            FLAGS             *
  230                 *******************************/

 prolog_flag(?Flag, ?Value) is nondet

Same as ISO current_prolog_flag/2. Maps version.

bug

- Should map relevant Quintus flag identifiers.

  238prolog_flag(version, Version) :-
  239    !,
  240    current_prolog_flag(version_data, swi(Major, Minor, Patch, _)),
  241    current_prolog_flag(arch, Arch),
  242    current_prolog_flag(compiled_at, Compiled),
  243    atomic_list_concat(['SWI-Prolog ',
  244                 Major, '.', Minor, '.', Patch,
  245                 ' (', Arch, '): ', Compiled], Version).
  246prolog_flag(Flag, Value) :-
  247    current_prolog_flag(Flag, Value).
  248
  249
  250                 /*******************************
  251                 *          STATISTICS          *
  252                 *******************************/
  253
  254%       Here used to be a definition of Quintus statistics/2 in traditional
  255%       SWI-Prolog statistics/2.  The current built-in emulates Quintus
  256%       almost completely.
  257
  258
  259                 /*******************************
  260                 *           DATE/TIME          *
  261                 *******************************/

 date(-Date) is det

Get current date as date(Y,M,D)

  267date(Date) :-
  268    get_time(T),
  269    stamp_date_time(T, DaTime, local),
  270    date_time_value(date, DaTime, Date).
  271
  272
  273                /********************************
  274                *          STYLE CHECK          *
  275                *********************************/

 no_style_check(Style) is det

Same as SWI-Prolog style_check(-Style). The Quintus option single_var is mapped to singleton.

See also

- style_check/1.

  284q_style_option(single_var, singleton) :- !.
  285q_style_option(Option, Option).
  286
  287no_style_check(QOption) :-
  288    q_style_option(QOption, SWIOption),
  289    style_check(-SWIOption).
  290
  291
  292                /********************************
  293                *         DIRECTIVES            *
  294                *********************************/

 mode(+ModeDecl) is det

Ignore a DEC10/Quintus :- mode(Head) declaration. Typically these declarations are written in operator form. The operator declaration is not part of the Quintus emulation library. The following declaration is compatible with Quintus:

:- op(1150, fx, [(mode)]).

  307mode(_).
  308
  309
  310                 /*******************************
  311                 *            TYPES             *
  312                 *******************************/

 simple(@Term) is semidet

Term is atomic or a variable.

  318simple(X) :-
  319    (   atomic(X)
  320    ->  true
  321    ;   var(X)
  322    ).
  323
  324
  325                 /*******************************
  326                 *            STREAMS           *
  327                 *******************************/

 current_stream(?Object, ?Mode, ?Stream)

SICStus/Quintus and backward compatible predicate. New code should be using the ISO compatible stream_property/2.

  334current_stream(Object, Mode, Stream) :-
  335    stream_property(Stream, mode(FullMode)),
  336    stream_mode(FullMode, Mode),
  337    (   stream_property(Stream, file_name(Object0))
  338    ->  true
  339    ;   stream_property(Stream, file_no(Object0))
  340    ->  true
  341    ;   Object0 = []
  342    ),
  343    Object = Object0.
  344
  345stream_mode(read,   read).
  346stream_mode(write,  write).
  347stream_mode(append, write).
  348stream_mode(update, write).

 stream_position(+Stream, -Old, +New)

True when Old is the current position in Stream and the stream has been repositioned to New.

deprecated

- New code should use the ISO predicates stream_property/2 and set_stream_position/2.

  358stream_position(Stream, Old, New) :-
  359    stream_property(Stream, position(Old)),
  360    set_stream_position(Stream, New).

 skip_line is det

 skip_line(Stream) is det

Skip the rest of the current line (on Stream). Same as skip(0'\n).

  369skip_line :-
  370    skip(10).
  371skip_line(Stream) :-
  372    skip(Stream, 10).
  373
  374
  375                 /*******************************
  376                 *         COMPILATION          *
  377                 *******************************/

 compile(+Files) is det

Compile files. SWI-Prolog doesn't distinguish between compilation and consult.

See also

- load_files/2.

  386:- meta_predicate
  387    compile(:).  388
  389compile(Files) :-
  390    consult(Files).
  391
  392                 /*******************************
  393                 *         ATOM-HANDLING        *
  394                 *******************************/

 atom_char(+Char, -Code) is det

atom_char(-Char, +Code) is det

Same as ISO char_code/2.

  401atom_char(Char, Code) :-
  402    char_code(Char, Code).

 midstring(?ABC, ?B, ?AC) is nondet

 midstring(?ABC, ?B, ?AC, LenA) is nondet

 midstring(?ABC, ?B, ?AC, LenA, LenB) is nondet

 midstring(?ABC, ?B, ?AC, LenA, LenB, LenC) is nondet

Too difficult to explain. See the Quintus docs. As far as I understand them the code below emulates this function just fine.

  412midstring(ABC, B, AC) :-
  413    midstring(ABC, B, AC, _, _, _).
  414midstring(ABC, B, AC, LenA) :-
  415    midstring(ABC, B, AC, LenA, _, _).
  416midstring(ABC, B, AC, LenA, LenB) :-
  417    midstring(ABC, B, AC, LenA, LenB, _).
  418midstring(ABC, B, AC, LenA, LenB, LenC) :-      % -ABC, +B, +AC
  419    var(ABC),
  420    !,
  421    atom_length(AC, LenAC),
  422    (   nonvar(LenA) ; nonvar(LenC)
  423    ->  plus(LenA, LenC, LenAC)
  424    ;   true
  425    ),
  426    sub_atom(AC, 0, LenA, _, A),
  427    LenC is LenAC - LenA,
  428    sub_atom(AC, _, LenC, 0, C),
  429    atom_length(B, LenB),
  430    atomic_list_concat([A,B,C], ABC).
  431midstring(ABC, B, AC, LenA, LenB, LenC) :-
  432    sub_atom(ABC, LenA, LenB, LenC, B),
  433    sub_atom(ABC, 0, LenA, _, A),
  434    sub_atom(ABC, _, LenC, 0, C),
  435    atom_concat(A, C, AC).
  436
  437
  438                 /*******************************
  439                 *           EXCEPTIONS         *
  440                 *******************************/

 raise_exception(+Term)

Quintus compatible exception handling

  446raise_exception(Term) :-
  447    throw(Term).

 on_exception(+Template, :Goal, :Recover)

  451:- meta_predicate
  452    on_exception(+, 0, 0).  453
  454on_exception(Except, Goal, Recover) :-
  455    catch(Goal, Except, Recover)