错误：超出本地堆栈

时间：2014-01-29 18:47:43

标签： prolog

Hi Every Body我在尝试运行此序言时出现此问题“ERROR：Out of local stack”

这是代码




:- redefine_system_predicate(write(_)).
:- redefine_system_predicate(readln(_)).



write(S) :-
    is_list(S) -> format('~s', [S]) ; format('~w', [S]).
write(A,B,C,D) :-
    maplist(write, [A,B,C,D]).
write(A,B,C) :-
    maplist(write, [A,B,C]).
readchar(S) :-
    get(C), atom_codes(S, [C]).
readln(A) :-
    system:readln(L), atomic_list_concat(L,' ',A).



go :-
    write("What is the patient's name? "),
    readln(Patient),
    hypothesis(Patient,Disease),
    write(Patient,"probably has ",Disease,"."),nl.



go :-
    write("Sorry, I don't seem to be able to"),nl,
    write("diagnose the disease."),nl.



symptom(Patient,fever) :-
    write("Does ",Patient," have a fever (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,rash) :-
    write("Does ",Patient," have a rash (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,headache) :-
    write("Does ",Patient," have a headache (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,runny_nose) :-
    write("Does ",Patient," have a runny_nose (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,conjunctivitis) :-
    write("Does ",Patient," have a conjunctivitis (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,cough) :-
    write("Does ",Patient," have a cough (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,body_ache) :-
    write("Does ",Patient," have a body_ache (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,chills) :-
    write("Does ",Patient," have a chills (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,sore_throat) :-
    write("Does ",Patient," have a sore_throat (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,sneezing) :-
    write("Does ",Patient," have a sneezing (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,swollen_glands) :-
    write("Does ",Patient," have a swollen_glands (y/n) ?"),
    response(Reply),
    Reply='y'.



hypothesis(Patient,measles) :-
    symptom(Patient,fever),
    symptom(Patient,cough),
    symptom(Patient,conjunctivitis),
    symptom(Patient,runny_nose),
    symptom(Patient,rash).



hypothesis(Patient,german_measles) :-
    symptom(Patient,fever),
    symptom(Patient,headache),
    symptom(Patient,runny_nose),
    symptom(Patient,rash).



hypothesis(Patient,flu) :-
    symptom(Patient,fever),
    symptom(Patient,headache),
    symptom(Patient,body_ache),
    symptom(Patient,conjunctivitis),
    symptom(Patient,chills),
    symptom(Patient,sore_throat),
    symptom(Patient,runny_nose),
    symptom(Patient,cough).



hypothesis(Patient,common_cold) :-
    symptom(Patient,headache),
    symptom(Patient,sneezing),
    symptom(Patient,sore_throat),
    symptom(Patient,runny_nose),
    symptom(Patient,chills).



hypothesis(Patient,mumps) :-
    symptom(Patient,fever),
    symptom(Patient,swollen_glands).



hypothesis(Patient,chicken_pox) :-
    symptom(Patient,fever),
    symptom(Patient,chills),
    symptom(Patient,body_ache),
    symptom(Patient,rash).



hypothesis(Patient,measles) :-
    symptom(Patient,cough),
    symptom(Patient,sneezing),
    symptom(Patient,runny_nose).



response(Reply) :-
    readchar(Reply),
    write(Reply),nl.

有什么建议吗？

3 个答案:

答案 0 :(得分：2)

你有一个循环：

readln(A) :- system:readln(L), atomic_list_concat(L,' ',A).

测试

1 ?- [user].
|: :- redefine_system_predicate(readln(_)).
|: readln(A) :- system:readln(L), atomic_list_concat(L,' ',A).
% user://1 compiled 0.03 sec, 2 clauses
true.

2 ?- readln(X).
ERROR: Out of local stack
3 ?-

另一个问题，但没有导致stackoverflow ... 如果您使用最近的SWI-Prolog（版本＆gt; = 7.0），请注意您对字符串'type'的测试：双引号文字不再是列表。

?- is_list("123").
false.

答案 1 :(得分：1)

“超出本地堆栈”意味着由于以下某些原因，您没有剩余内存来计算结果：

  • 通常在某处有无限循环。在递归循环中缺少基本案例。
  • 你工作的名单太大了。
  • 有很多回溯，翻译无法处理。

我认为第一个适用于readln(A) :- system:readln(L), atomic_list_concat(L,' ',A).

无论如何，如果您需要更多内存，可以使用SWI-Prolog中的set_prolog_stack/2扩展堆栈。

答案 2 :(得分：0)

我通过使用新版本的SWI-Prolog解决问题并删除write和readln语句，代码如下所示。 




:- redefine_system_predicate(write(_)).
:- redefine_system_predicate(readln(_)).



write(A,B,C,D) :-
    maplist(write, [A,B,C,D]).
write(A,B,C) :-
    maplist(write, [A,B,C]).
readchar(S) :-
    get(C), atom_codes(S, [C]).



go :-
    write("What is the patient\'s name? "),
    readln(Patient),
    hypothesis(Patient,Disease),
    write(Patient,"probably has ",Disease,"."),nl.



go :-
    write("Sorry, I don't seem to be able to"),nl,
    write("diagnose the disease."),nl.



symptom(Patient,fever) :-
    write("Does ",Patient," have a fever (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,rash) :-
    write("Does ",Patient," have a rash (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,headache) :-
    write("Does ",Patient," have a headache (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,runny_nose) :-
    write("Does ",Patient," have a runny_nose (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,conjunctivitis) :-
    write("Does ",Patient," have a conjunctivitis (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,cough) :-
    write("Does ",Patient," have a cough (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,body_ache) :-
    write("Does ",Patient," have a body_ache (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,chills) :-
    write("Does ",Patient," have a chills (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,sore_throat) :-
    write("Does ",Patient," have a sore_throat (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,sneezing) :-
    write("Does ",Patient," have a sneezing (y/n) ?"),
    response(Reply),
    Reply='y'.



symptom(Patient,swollen_glands) :-
    write("Does ",Patient," have a swollen_glands (y/n) ?"),
    response(Reply),
    Reply='y'.



hypothesis(Patient,measles) :-
    symptom(Patient,fever),
    symptom(Patient,cough),
    symptom(Patient,conjunctivitis),
    symptom(Patient,runny_nose),
    symptom(Patient,rash).



hypothesis(Patient,german_measles) :-
    symptom(Patient,fever),
    symptom(Patient,headache),
    symptom(Patient,runny_nose),
    symptom(Patient,rash).



hypothesis(Patient,flu) :-
    symptom(Patient,fever),
    symptom(Patient,headache),
    symptom(Patient,body_ache),
    symptom(Patient,conjunctivitis),
    symptom(Patient,chills),
    symptom(Patient,sore_throat),
    symptom(Patient,runny_nose),
    symptom(Patient,cough).



hypothesis(Patient,common_cold) :-
    symptom(Patient,headache),
    symptom(Patient,sneezing),
    symptom(Patient,sore_throat),
    symptom(Patient,runny_nose),
    symptom(Patient,chills).



hypothesis(Patient,mumps) :-
    symptom(Patient,fever),
    symptom(Patient,swollen_glands).



hypothesis(Patient,chicken_pox) :-
    symptom(Patient,fever),
    symptom(Patient,chills),
    symptom(Patient,body_ache),
    symptom(Patient,rash).



hypothesis(Patient,measles) :-
    symptom(Patient,cough),
    symptom(Patient,sneezing),
    symptom(Patient,runny_nose).



response(Reply) :-
    readchar(Reply),
    write(Reply),nl.

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