可能重复：
SWI Prolog 中的刽子手游戏
我正在尝试使用以下内容在 SWI Prolog 中增强一个简单的刽子手游戏：
1）通过跟上到目前为止已经猜到的错误字母。如果用户猜出一个已经猜错的字母，程序应该说“你猜对了！” 并继续游戏而不增加计数器。
2）最后，添加一个计数器，计算错误猜测的次数，并在达到一定数量时退出游戏。程序应该告诉用户他们输了，显示这句话的真正含义，然后终止。重复的猜测不应被视为错误。
我怎样才能将这些谓词放在一起，以便我的程序运行上述增强功能？
1)
alreadyGuessed(Guess, AnsCodes) :-
memberchk(Guess, AnsCodes).
2)
processGuess(AnsList, BlankList, _, CountFailed) :-
( CountFailed == 5
-> format('Sorry, game over. You didn\'t guess (~s)~n', [AnsList])
; write('Nope!'),
CountFailed1 is CountFailed + 1,
getGuess(AnsList, BlankList, CountFailed1)
).
我试图做的是：
扩展谓词 getGuess(AnsList, BlankList, CountFailed)
在我进行更改之前，我会为您提供运行版本的代码和注释。
编辑：程序现在运行，直到你犯了 5 个错误。像现在这样运行它，?- hangman(0).
我只需要不计算到目前为止已使用的字母作为错误答案并显示上面列出的适当消息。我会通过再写一个谓词来做到这一点processGuess吗？
% This top-level predicate runs the game. It prints a
% welcome message, picks a phrase, and calls getGuess.
% Ans = Answer
% AnsList = AnswerList
hangman(CountFailed):-
getPhrase(Ans),
!,
write('Welcome to hangman.'),
nl,
name(Ans,AnsList),
makeBlanks(AnsList, BlankList),
getGuess(AnsList,BlankList, CountFailed).
% Randomly returns a phrase from the list of possibilities.
getPhrase(Ans):-
phrases(L),
length(L, X),
R is random(X),
N is R+1,
getNth(L, N, Ans).
% Possible phrases to guess.
phrases(['a_picture_is_worth_a_thousand_words','one_for_the_money','dead_or_alive','computer_science']).
% Asks the user for a letter guess. Starts by writing the
% current "display phrase" with blanks, then asks for a guess and
% calls process on the guess.
getGuess(AnsList, BlankList, CountFailed):-
name(BlankName, BlankList),
write(BlankName),
nl,
write('Enter your guess, followed by a period and return.'),
nl,
read(Guess),
!,
name(Guess, [GuessName]),
processGuess(AnsList,BlankList,GuessName, CountFailed).
% Process guess takes a list of codes representing the answer, a list of codes representing the current
% "display phrase" with blanks in it, and the code of the letter that was just guessed. If the guess
% was right, call substitute to put the letter in the display phrase and check for a win. Otherwise, just
% get another guess from the user.
processGuess(AnsList,BlankList,GuessName, CountFailed):-
member(GuessName,AnsList),
!,
write('Correct!'),
nl,
substitute(AnsList, BlankList, GuessName, NewBlanks),
checkWin(AnsList,NewBlanks, CountFailed).
processGuess(AnsList, BlankList, _, CountFailed) :-
( CountFailed == 5
-> format('Sorry, game over. You didn\'t guess (~s)~n', [AnsList])
; write('Nope!'),
nl,
CountFailed1 is CountFailed + 1,
getGuess(AnsList, BlankList, CountFailed1)
).
% Check to see if the phrase is guessed. If so, write 'You win' and if not, go back and get another guess.
checkWin(AnsList, BlankList, CountFailed):-
name(Ans, AnsList),
name(BlankName, BlankList),
BlankName = Ans,
!,
write('You win!').
checkWin(AnsList, BlankList, CountFailed):-
getGuess(AnsList, BlankList, CountFailed).
% getNth(L,N,E) should be true when E is the Nth element of the list L. N will always
% be at least 1.
getNth([H|T],1,H).
getNth([H|T],N,E):-
N1 is N-1,
getNth(T,N1,E1),
E=E1.
% makeBlanks(AnsList, BlankList) should take an answer phrase, which is a list
% of character codes that represent the answer phrase, and return a list
% where all codes but the '_' turn into the code for '*'. The underscores
% need to remain to show where the words start and end. Please note that
% both input and output lists for this predicate are lists of character codes.
% You can test your code with a query like this:
% testMakeBlanks:- name('csc_is_awesome', List), makeBlanks(List, BlankList), name(Towrite, BlankList), write(Towrite).
makeBlanks(AnsCodes, BlankCodes) :-
maplist(answer_blank, AnsCodes, BlankCodes).
answer_blank(Ans, Blank) :-
Ans == 0'_ -> Blank = Ans ; Blank = 0'* .
% substitute(AnsList, BlankList, GuessName, NewBlanks) Takes character code lists AnsList and BlankList,
% and GuessName, which is the character code for the guessed letter. The NewBlanks should again be a
% character code list, which puts all the guesses into the display word and keeps the *'s and _'s otherwise.
% For example, if the answer is 'csc_is_awesome' and the display is 'c*c_**_*******' and the guess is 's', the
% new display should be 'csc_*s_***s***'.
% You can test your predicate with a query like this:
% testSubstitute:- name('csc_is_awesome', AnsList), name('c*c_**_*******', BlankList), name('s',[GuessName]), substitute(AnsList, BlankList, GuessName, NewBlanks),
% name(Towrite, NewBlanks), write(Towrite).
% Also, since the predicate doesn't deal directly with character codes, this should also work:
% substitute(['c','s','c'],['c','*','c'],'s',L). L should be ['c','s','c'].
substitute(AnsCodes, BlankCodes, GuessName, NewBlanks) :-
maplist(place_guess(GuessName), AnsCodes, BlankCodes, NewBlanks).
place_guess(Guess, Ans, Blank, Display) :-
Guess == Ans -> Display = Ans ; Display = Blank.