网络书屋(Web Reading Room)

A blogging framework for hackers.

Prolog小游戏

games

prolog 作为一门logic programming language,逻辑推理是它的强项。游戏也是一个逻辑推理的过程,prolog照样可以,通过该游戏的写作可以让你熟悉

  1. 事实和规则。
  2. built-in predicates.
  3. IO
  4. cut-fail操作

游戏源代码如下,进一步参考prolog教程.

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:-dynamic here/1.

room(kitchen).
room(office).
room(hall).
room('dining room').
room(cellar).
door(office, hall).
door(kitchen, office).
door(hall, 'dining room').
door(kitchen, cellar).
door('dining room', kitchen).

location(desk, office).
location(apple, kitchen).
location(flashlight, desk).
location('washing machine', cellar).
location(nani, 'washing machine').
location(broccoli, kitchen).
location(crackers, kitchen).
location(knife, kitchen).
location(computer, office).

location(envelope, desk).
location(stamp, envelope).
location(key, envelope). /* more interesting thing*/

edible(apple).
edible(crackers).
tastes_yucky(broccoli).

/* You are here now in the  game.*/
here(kitchen).
where_food(X,Y) :- location(X,Y),edible(X).
where_food(X,Y) :- location(X,Y),tastes_yucky(X).

connect(X,Y):-door(X,Y).
connect(X,Y):-door(Y,X).


/*list all things in the correspondign room*/
list_things(Place) :- location(X,Place),tab(2),write(X),nl,fail.

list_things(_).  /* always correct  AnyPlace's value we don't care, 只能用_ underscore)*/


list_things_to_eat(Place) :- where_food(X,Place),tab(2),write(X),nl,fail.
list_things_to_eat(_) .


list_connections(Place) :- connect(X,Place),tab(2),write(X),nl,fail.
list_connections(_).


look:- here(Place), write('You are in the '),write(Place),write(' now!'),nl,write('You can see:'),nl,
list_things(Place),write('what the things you can eat  are below:'),nl,list_things_to_eat(Place),
write('You can also go to '),nl,list_connections(Place).






c_to_f(C,F):- F is C*9/5+32.
freezeing(F):-F=<32.

goto(Place) :- can_go(Place),move(Place),look.
can_go(Place) :- here(X),connect(X,Place).
can_go(_) :- write('You can''t get there from here.'),nl,fail.
move(Place):- retract(here(Y)),asserta(here(Place)).


take(X):- can_take(X),take_object(X).

can_take(Thing) :-here(Place),location(Thing,Place).
can_take(Thing) :- write('There is no '),write(Thing),write(' Here'),nl,fail.

take_object(X):- retract(location(X,_)),asserta(hava(X)),write('taken'),nl.


backtracking_assert(X):- asserta(X).
backtracking_assert(X):- retract(X),fail.


is_contained_in(T1,T2) :- location(T1,T2).
is_contained_in(T1,T2) :- location(X,T2),is_contained_in(T1,X).


object(candle,red   ,small,1).
object(apple ,red   ,small,1).
object(apple ,green ,small,1).
object(apple ,blue  ,big,50).
object(desk,brwon,dimension(6,3,3),90).
object(desk,color(brwon),size(dimension(6,3,3)),weight(90)).
object(desk,color(brwon),size(large),weight(90)).

location_s(object(candle,red    ,small,1),kitchen).
location_s(object(apple ,bluired ,small,1),kitchen).
location_s(object(apple ,green   ,small,1),kitchen).
location_s(object(apple ,blue  ,big,50),kitchen).


can_take_s(Thing) :- here(Room),location_s(object(Thing,_,small,_),Room).
can_take_s(Thing) :- here(Room),location_s(object(Thing,_,big,_),Room),write('The '),write(Thing),
                write(' is too big to carry!'),nl,fail.
can_take_s(Thing) :- here(Room),not(location_s(object(Thing,_,_,_),Room)),write('There is no '),
                write(Thing),write('Here.'),nl,fail.

list_things_s(Place) :- location_s(object(Thing,Color,Size,Weight),Place),
    write('A '),write(Size),tab(1),write(Color),tab(1),write(Thing),write(',weighing '),
    write_weight(Weight),nl,fail.
list_things_s(_).

write_weight(1):-write('1 pound').
write_weight(W):-W>1,write(W),write(' pounds').


loc_list([apple,broccoil,crackers],kitchen).
loc_list([desk,computer],office).
loc_list([flashlight,envelope],desk).
loc_list([stamp,key],envelope).
loc_list(['Washing machine'],cellar).
loc_list([nani],'Washing machine').
loc_list([],hall). /* empty list*/

/*length1([zha,df,gs],H).*/
length1([],0).
length1([H|T],N) :- length1(T,M),N is M+1.

member(X,[X|List]).
member(X,[Element|List]) :- member(X,List).

prefix([],List).
prefix([X|Prefix],[X|List]):- prefix(Prefix,List).

suffix(Suffix,Suffix).
prefix(Suffix,[X|List]) :- suffix(Suffix,List).

vowel(X) :- member(X,[a,e,i,o,u]).
digit(D) :- member(D,['0','1','2','3','4','5','6','7','8','9']).

/*reverse([ ],[ ]).
reverse([X|L],Rev) :- reverse(L,RL), append(RL,[X],Rev).*/

/*reverse([a,b,v],Rl).*/
reverse([ ],[ ]).
reverse(L,RL) :- reverse(L,[ ],RL).

reverse([ ],RL,RL).
reverse([X|L],PRL,RL) :- reverse(L,[X|PRL],RL).

/* isort([6,3,6,2,4,64,234],Sl) */

isort([ ],[ ]).
isort([X|UnSorted],AllSorted) :- isort(UnSorted,Sorted),
                                 insert(X,Sorted,AllSorted).

insert(X,[ ],[X]).
insert(X,[Y|L],[X,Y|L]) :- X =< Y.
insert(X,[Y|L],[Y|IL]) :-  X > Y, insert(X,L,IL).


facTail(0,1).
facTail(N,F) :- N > 0, facTail(N,1,F).

facTail(1,F,F).
facTail(N,PP,F) :- N > 1, NPp is N*PP, M is N-1,
       facTail(M,NPp,F).


fibTail(0,1).
fibTail(1,1).
fibTail(N,F) :- N > 1, fibTail(N,1,1,F).

fibTail(2,F1,F2,F) :- F is F1 + F2.
fibTail(N,F1,F2,F) :- N > 2, N1 is N - 1, NF1 is F1 + F2,
    fibTail(N1,NF1,F1,F).

/*
primes(PL) :- natlist(2,L2), sieve(L2,PL).

sieve([ ],[ ]).
sieve([P|L],[P|IDL]) :- sieveP(P,L,PL), sieve(PL,IDL).

sieveP(P,[ ],[ ]). 
sieveP(P,[N|L],[N|IDL]) :- N mod P  >  0, sieveP(P,L,IDL).
sieveP(P,[N|L],   IDL)  :- N mod P =:= 0, sieveP(P,L,IDL).
*/
/*
merge( List1, List2, List3 ) :-
 ( List1 = [], !, List3 = List2 );
 ( List2 = [], !, List3 = List1 );
 ( List1 = [X|L1], List2 = [Y|L2 ),
((X < Y, ! Z = X, merge( L1, List2, L3 ) );
( Z = Y, merge( List1, L2, L3 ) )),
  List3 = [Z|L3].
*/

merge([],List2,List2).
merge(List1,[],List1).

merge([X|List1],[Y|List2],[Z|List3]) :- X<Y,!,merge(List1,List2,List3).
merge(List1,[Y|List2],[Y|List3]) :- merge(List1,List,List3).