predicate

问题 Say I have a list of all the integers from 2 to 20 . [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20] I also have a function f x that returns either True or False . When I apply this function to the element at position n and it equals to True , I want to remove it and its precedent element (which is the element at position n-1 ). I want to keep doing this until the list is empty of elements for which the function equals to True , as well as their preceding elements. Example: Let's say that

问题 Say I have a list of all the integers from 2 to 20 . [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20] I also have a function f x that returns either True or False . When I apply this function to the element at position n and it equals to True , I want to remove it and its precedent element (which is the element at position n-1 ). I want to keep doing this until the list is empty of elements for which the function equals to True , as well as their preceding elements. Example: Let's say that

问题 Initially got following codes. columnA and columnB only need to update if got changes. (I have columnC and so on also but just elaborate short one here). But the updatedBy and updatedTime always need to update. The following way is doing checking for each changes and updating the columns correspondingly. But this is tedious. if(isChangeColumnA && isChangeColumnB) { repo.partialUpdate(product, p=> p.columnA, p=> p.columnB, p=> p.UpdatedBy, p=> p.UpdatedTime) } else if (isChangeColumnA) { repo

问题 I am manually building a predicate for filtering data in a CollectionView and I want to add the ability to filter a particular field via a user supplied Regex. Writing the predicate directly would give something like: string userRegex = "abc.+"; Predicate<object> myPredicate = p => Regex.IsMatch(((MyType).p).MyField, userRegex); So I could pass the pattern in to my Predicate Factory and do something like this (off the top of my head and not tried - not sure about the Call syntax): string

问题 My vertice properties partly contain objects like e.g. a File object. When searching with "has" I would like to search for Files by path. I think some kind of text comparison predicates that would do the "toString()" conversion might be helpful here. Are there any standard predicates like this in gremlin/tinkerpop or do I have to implement these my self? I found two related questions in stackoverflow: Gremlin.net textContains equivalent How Gremlin query same sql like for search feature And

问题 For fun I've been attempting to write a Knight's Tour (https://en.wikipedia.org/wiki/Knight%27s_tour) solver in gprolog using Warnsdorf's rule. I found another SO post asking about efficiency that provided a solution in B-prolog: knight's tour efficient solution. My problem arises with the following section: :- table warnsdorff(+,+,+,+,+,-,-,min). warnsdorff(R, C, X, Y, Visits, NewX, NewY, Score) :- possible_knight_moves(R, C, X, Y, Visits, NewX, NewY), possible_moves_count(R, C, NewX, NewY,

问题 I am trying to make a function which takes as input a predicate and a list. and removes all elements from the list for which the predicate holds. What I have so far is the following function: removeif :: func->[a]->[a] removeif [] = [] removeif func (h:t)= if func then delete h (h:t) else removeif func t I am confused about the func part of the func->[a]->[a] because I don't know how should I tell that its a predicate. For example what I want is that I give from the terminal this command

问题 I am trying to build a search view for an existing CoreData app (simple logging app). I have all the data stored with CoreData and is fetched with the @FetchRequest : @State private var searchPredicate: NSPredicate? = NSPredicate(format: "title contains[c] %@", "") @FetchRequest( entity: Item.entity(), sortDescriptors: [NSSortDescriptor(keyPath: \Item.title, ascending: true)], predicate: NSPredicate(format: "title contains[c] %@", "h") ) var items: FetchedResults<Item> It now only fetches the

问题 I have a String as "ishant" and a Set<String> as ["Ishant", "Gaurav", "sdnj"] . I need to write the Predicate for this. I have tried as below code, but it is not working Predicate<Set<String>,String> checkIfCurrencyPresent = (currencyList,currency) -> currencyList.contains(currency); How can I create a Predicate which will take Set<String> and String as a parameter and can give the result? 回答1: A Predicate<T> which you're currently using represents a predicate (boolean-valued function) of one

问题 I am trying to remove elements from a std::list and keep some stats of deleted elements. In order to do so, I use the remove_if function from the list, and I have a predicate. I would like to use this predicate to gather statistics. Here is the code for the predicate: class TestPredicate { private: int limit_; public: int sum; int count; TestPredicate(int limit) : limit_(limit), sum(0), count(0) {} bool operator() (int value) { if (value >= limit_) { sum += value; ++count; // Part where I