Prolog 中的字幕

Question

从html来看，marquee显然是语义网的顶峰。或者更确切地说，它的最低点与闪烁标签并排。无论如何，我们如何在 Prolog 中表示选取框？换句话说，如何定义一个关系marquee/2以使以下内容成立：

?- marquee("Prolog is marquee ready! ",M).
   M = "Prolog is marquee ready! "
;  M = "rolog is marquee ready! P"
;  M = "olog is marquee ready! Pr"
;  M = "log is marquee ready! Pro"
;  M = "og is marquee ready! Prol"
;  M = "g is marquee ready! Prolo"
;  M = " is marquee ready! Prolog"
;  M = "is marquee ready! Prolog "
;  M = "s marquee ready! Prolog i"
;  M = " marquee ready! Prolog is"
;  M = "marquee ready! Prolog is "
;  ... .
?- M=[m|_],marquee("Prolog is marquee ready! ",M).
   M = "marquee ready! Prolog is "
;  M = "marquee ready! Prolog is "
;  M = "marquee ready! Prolog is " % infinitely many redundant answers
;  ... .

那么如何仅使用Prolog prologuemarquee/2在ISO Prolog中进行定义呢？上面的双引号假设，并且需要设置答案写入选项才能获取整个字符串。set_prolog_flag(double_quotes, chars)max_depth(0)

我尝试过，member/2但它只描述了字符，然后我尝试了nth0/3，nth1/3但它们只按顺序描述了两个字符，如下所示：

?- T = "Prolog is marquee ready! ", nth1(I,T,A),nth0(I,T,B).
   T = "Prolog is marquee ready! ", I = 1, A = 'P', B = r
;  T = "Prolog is marquee ready! ", I = 2, A = r, B = o
;  ... .

编辑：关于重复的一项澄清。它们应该无缝地结合在一起，就像

?- marquee("! ",M).
   M = "! "
;  M = " !"
;  M = "! "
;  M = " !"
;  M = "! "
;  M = " !"
;  M = "! "
;  M = " !"
;  M = "! "
;  M = " !"
;  ... .

Answer 1

首先，向这个答案和作者 @brebs致敬。

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我看着marquee_/3……，又用append/3混乱的论点回头看着我\xe2\x80\x94。

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所以这是最低限度更新的版本marquee/2：

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\n选取框(L,M) :-\n 附加(L,R,LD),\n   附加(R,M,LD)。% 为：marquee_(LD,R,M)\n

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示例查询：

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?- marquee("prolog",Xs).\n   Xs = "prolog"\n;  Xs = "rologp"\n;  Xs = "ologpr"\n;  Xs = "logpro"\n;  Xs = "ogprol"\n;  Xs = "gprolo"\n;  Xs = "prolog"\n;  Xs = "rologp"\n;  ... .\n\n?- marquee("",Xs).\n   Xs = []\n;  Xs = []\n;  ... .\n

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Answer 2

这是一个替代解决方案（在评论中提出建议后更新），希望这可以解决任务

marquee(String,String).
marquee([H|T],R):-
    append(T,[H],NewEl),
    marquee(NewEl,R).


?- marquee("Prolog is marquee ready! ", M).
M = ['P', r, o, l, o, g, ' ', i, s, ' ', m, a, r, q, u, e, e, ' ', r, e, a, d, y, !, ' '];
M = [r, o, l, o, g, ' ', i, s, ' ', m, a, r, q, u, e, e, ' ', r, e, a, d, y, !, ' ', 'P'];
...

?- M=[m|_],marquee("Prolog is marquee ready! ",M).
M = [m, a, r, q, u, e, e, ' ', r, e, a, d, y, !, ' ', 'P', r, o, l, o, g, ' ', i, s, ' '];
M = [m, a, r, q, u, e, e, ' ', r, e, a, d, y, !, ' ', 'P', r, o, l, o, g, ' ', i, s, ' '];
...