predicates

问题 I have the following code that helps me build a lambda expression via reflection. However when I try to compare versus a Date it converts my value to a full DateTime stamp. How can I get it to build my predicate so it will only compare the short date? System.Reflection.PropertyInfo propInfo = typeof(T).GetProperty(property); Type propertyType = propInfo.PropertyType; if (Utilities.IsNullableType(propertyType)) { propertyType = Nullable.GetUnderlyingType(propertyType); } ParameterExpression

问题 I have an Artist object with a .localConcerts fetched property (basically a subset of the full . concerts set), can I use that property inside my NSFetchedResultsController predicate? Here's what I'm trying: NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Artist" inManagedObjectContext:context]; [request setEntity:entity]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"localConcerts.@count > 0"]; [request

问题 I run into problem while reading a book. I see a program use predicate "simple" ( I guess simple/1 ). I don't know what is the meaning of this predicate, I can't find it with ?-help(simple) in the console. But when I tried with some queries in console, it worked something like: 5 ?- simple(p(x)). false. 6 ?- simple(mia). true. 7 ?- simple(Mia). true. 8 ?- simple(f(Mia)). false. I guess it is some sort of predicate to determine if the argument was Terms(or Variables) or Complex Terms. 回答1: The

问题 I run into problem while reading a book. I see a program use predicate "simple" ( I guess simple/1 ). I don't know what is the meaning of this predicate, I can't find it with ?-help(simple) in the console. But when I tried with some queries in console, it worked something like: 5 ?- simple(p(x)). false. 6 ?- simple(mia). true. 7 ?- simple(Mia). true. 8 ?- simple(f(Mia)). false. I guess it is some sort of predicate to determine if the argument was Terms(or Variables) or Complex Terms. 回答1: The

问题 This question already has answers here : Is it possible to retrieve lambda expression at runtime (2 answers) Closed 5 years ago . For debugging purposes I am trying to create string representations of lambda expressions (specifically of Predicate s, though it would be interesting for other lambda expressions too) in Java 8. My idea would be something like this: public class Whatever { private static <T> String predicateToString(Predicate<T> predicate) { String representation = ... // do magic

问题 I am currently learning about predicate logic in Prolog. I am having trouble answering a question on the topic and would like to know the steps one one take to solve such a question using Prolog predicates. I have a scenario which must be represented in Prolog predicates using only two different predicate names. A and B are married B likes C C and D are married D likes E F likes B E likes B E and G are married A likes G 回答1: Just write down what it says. are_married(a,b). likes(b,c). And so

问题 is there a way to get a sorted collection from a hazelcast predicate? i have found that hazelcast offers a pagingpredicate for this purpose but i am not interested in the paging behavior (at least for now). even if one does use this pagingpredicate, does it make sure that the whole collection is sorted and not just the items in a particular page? and also if there is any way to disable the paging completely? i am interested in getting the results in sorted form and not in sorting the

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 5 years ago . I am writing a Sudoku-Solver with PROLOG. I want the solver to work with all possible sizes of Sudokus, so naturally I need to construct predicates which take a variable number of arguments. (For example to construct the "blocks" in the Sudoku.) How can I construct or simulate

问题 consider following rules in the parser: expression : IDENTIFIER | (...) | procedure_call // e.g. (foo 1 2 3) | macro_use // e.g. (xyz (some datum)) ; procedure_call : '(' expression expression* ')' ; macro_use : '(' IDENTIFIER datum* ')' ; and // Note that any string that parses as an <expression> will also parse as a <datum>. datum : simple_datum | compound_datum ; simple_datum : BOOLEAN | NUMBER | CHARACTER | STRING | IDENTIFIER ; compound_datum : list | vector ; list : '(' (datum+ ( '.'

问题 My C++ is a little rusty as of late. Can one of you gurus help me define a SORT predicate, for a Container Class, with a template parameter which it self is a another class. template <class Element> class OrderedSequence // Maintains a sequence of elements in // ascending order (by "<"), allowing them to be retrieved // in that order. { public: // Constructors OrderedSequence(); OrderedSequence(const OrderedSequence<Element>&); // Destructor ~OrderedSequence(); // destructor OrderedSequence