Sorting 球拍中的奇怪行为
我有以下定义:Sorting 球拍中的奇怪行为,sorting,hashmap,racket,predicate,Sorting,Hashmap,Racket,Predicate,我有以下定义: (struct type (parent dirty) #:mutable #:transparent) (define types (make-hash)) (define (add-key predicate parent) (begin (hash-ref! types parent (type empty #t)) ;;if the parent doesn't exist, is created with no pa
(struct type (parent dirty) #:mutable #:transparent)
(define types (make-hash))
(define (add-key predicate parent)
(begin
(hash-ref! types parent (type empty #t)) ;;if the parent doesn't exist, is created with no parent.
(let([node (hash-ref types predicate #f)])
(if(or (boolean? node) ;;the node is not on the list
(not(equal? (type-parent node) parent))) ;;the node has a different parent
(hash-set! types predicate (type parent #t))
(printf "nothing to do\n")
))))
(define (ancestor? predicate1 predicate2)
(let ([node (hash-ref types predicate2 #f)])
(cond [(false? node)(error "following predicate is not in types: " predicate2)]
[(empty? (type-parent node)) #f]
[(equal? (type-parent node) predicate1) #t]
[else (ancestor? predicate1 (type-parent node))])))
它似乎工作得很好,我可以做以下事情:
> (ancestor? integer? even?)
#t
> (ancestor? list? even?)
#f
> (ancestor? integer? odd?)
#t
>
我似乎只对sort
as(sort'(整数?奇数?数字?列表?偶数?)祖先?
引发以下错误:以下谓词不在类型中:integer?
当然,这是在我的实现中定义的。问题是我确信键值对存在,我可以操纵它,我可以手动运行祖先的每一行代码。。。我真的很困惑是什么导致了这一切。。。有什么想法吗
我照原样把你的代码放进了一个文件
为祖先?
:添加第一行(displayln`(祖先?、谓词1、谓词2))
或添加(跟踪祖先?
(在之后(需要球拍/跟踪)
)
这显示了在代码中被破坏的违规调用:(祖先?'odd?'integer?
会导致该错误
(我不知道你的代码在做什么:这个想法是很容易机械地导出问题。)注意:如果你在查询之前对树进行线性预处理,有一个非常可爱的算法可以让你在固定时间内进行查询。请参阅:更仔细地阅读您的问题:当您说(排序)(整数?奇数?列表?偶数?)
,您的意思是(排序(整数?奇数?列表?偶数?)
?