Example of an .exe compiled by swi-prolog that can accept arguments

Question

I would appreciate your help after struggling 4 hours to the problem:

I need to create an exe file (on windows) from prolog script. For example, main.pl has inside:

day(monday).
day(tuesday).
day(wednesday).
day(thursday).
day(friday).    % let's stop here

I would like to compile this script, produce prog.exe file and then be able to do the following runs:

$ prog.exe --term sunday
 false
$ prog.exe --term monday
 true
$ prog.exe --goal day(friday)
 true
$ prog.exe --goal fun(foo)
 false

if flags are difficult non flag version with input goals will be also very helpful for me.

I tried to read compiling pages on swi-prolog page but got confused. I can not print anything on the standard output stream. Also I did not understand how flags works.

tried the example they have on swi-prolog site but I dont understand why nothing is printed. With the below script I can create exe file with command save(prog), but then while running prog.exe nothing is printed out.

:- ['main'].

main :-
        pce_main_loop(main).

main(Argv) :-
        write('hello word').

save(Exe) :-
        pce_autoload_all,
        pce_autoload_all,
        qsave_program(Exe,
                      [ emulator(swi('bin/xpce-stub.exe')),
                        stand_alone(true),
                        goal(main)
                      ]).

Answer 1

SWI-Prolog contains the optparse library which you can use for commandline arguments parsing.

opts_spec(
    [ [opt(day), type(atom),
        shortflags([d]), longflags(['term', 'day']),
        help('name of day')]

    , [opt(goal),
        shortflags([g]), longflags([goal]),
        help('goal to be called')]
    ]
).

% days
day(monday).
day(tuesday).
day(wednesday).
day(thursday).
day(friday).


main :-
    opts_spec(OptsSpec),
    opt_arguments(OptsSpec, Opts, _PositionalArgs),
    writeln(Opts),
    memberchk(day(Day), Opts),
    memberchk(goal(Goal), Opts),
    (nonvar(Day) -> call_call(day(Day), Result), writeln(Result) ; true),
    (nonvar(Goal) -> call_call(Goal, Result), writeln(Result) ; true),
    halt.

call_call(Goal, true) :-
    call(Goal), !.

call_call(_Goal, false).

You can compile and use the above code like this. (Tested only on Ubuntu, sorry, I cannot help regarding Windows.)

$ swipl -o day.exe -g main -c day.pl

$ ./day.exe --term monday
[goal(_G997),day(monday)]
true

$ ./day.exe --goal "day(sunday)"
[day(_G1009),goal(day(sunday))]
false

Answer 2

I will refer to eight_puzzle.pl, the module I posted for another answer as test case. Then I write a new file (say p8.pl) with a test argument line usage, compile and run

:- use_module(eight_puzzle).

go :-
    current_prolog_flag(argv, Argv),
    writeln(argv:Argv),
    (   nth1(Test_id_flag, Argv, '--test_id'),
        Test_id_pos is Test_id_flag+1,
        nth1(Test_id_pos, Argv, Id)
    ->  atom_concat(test, Id, Func)
    ;   Func = test1
    ),
    forall(time(call(eight_puzzle:Func, R)), writeln(R)).

to compile I used the documentation section 2.10.2.4 from 2.10 Compilation

swipl -O --goal=go --stand_alone=true -o p8 -c p8.pl

and to run with specified option:

./p8 --test_id 0

I'm running Ubuntu, but there should be no differences on Windows.

argv:[./p8,--test_id,0]
% 4,757 inferences, 0.003 CPU in 0.003 seconds (100% CPU, 1865842 Lips)
[4,3,6,7,8]
% 9,970 inferences, 0.005 CPU in 0.005 seconds (100% CPU, 2065656 Lips)
[4,3,6,7,4,5,8,7,4,5,8,7,4,5,8]
...

HTH