language-features

问题 When either hashCode() or == operator is overridden in a class, the dart analyzer warns, saying that the other method should also be overridden. Can I implement a similar case on other methods? Or is this feature a special case provided by Dart Analyzer? For exmaple, class A { void method1() {} void method2() {} } class B extends A { @override void method1() {} } At this point I want to produce a warning that class B should also override method2(). Is that possible? 回答1: What you are seeing

问题 When either hashCode() or == operator is overridden in a class, the dart analyzer warns, saying that the other method should also be overridden. Can I implement a similar case on other methods? Or is this feature a special case provided by Dart Analyzer? For exmaple, class A { void method1() {} void method2() {} } class B extends A { @override void method1() {} } At this point I want to produce a warning that class B should also override method2(). Is that possible? 回答1: What you are seeing

来源： https://stackoverflow.com/questions/1610337/how-can-i-find-the-current-windows-language-from-cmd

问题 I'm not quite understanding why there are finalizers in languages such as java and c#. AFAIK, they: are not guaranteed to run (in java) if they do run, they may run an arbitrary amount of time after the object in question becomes a candidate for finalization and (at least in java), they incur an amazingly huge performance hit to even stick on a class. So why were they added at all? I asked a friend, and he mumbled something about "you want to have every possible chance to clean up things like

问题 Why are these not equivalent? show $ if someCondition then someInt else some double and if someCondition then show someInt else show someDouble I understand that if you isolate the if ... else part in the first example to an expression by itself then you can't represent its type with an anonymous sum type, the kind of Int | Double , like something you could do easily in TypeScript (mentioning TypeScript because it is the langauge I used often and that supports Sum types), and would have to

问题 This question already has answers here : Is there an equivalent of the __noSuchMethod__ feature for properties, or a way to implement it in JS? (5 answers) Closed 5 years ago . The Spider-Monkey JavaScript engine implements the __noSuchMethod__ callback function for JavaScript Objects. This function is called whenever JavaScript tries to execute an undefined method of an Object. I would like to set a callback function to an Object that will be called whenever an undefined property in the

问题 This question already has answers here : Is there an equivalent of the __noSuchMethod__ feature for properties, or a way to implement it in JS? (5 answers) Closed 5 years ago . The Spider-Monkey JavaScript engine implements the __noSuchMethod__ callback function for JavaScript Objects. This function is called whenever JavaScript tries to execute an undefined method of an Object. I would like to set a callback function to an Object that will be called whenever an undefined property in the

问题 In some code I saw recently there was a structure defined like this: typedef struct tagMyStruct { int numberOne; int numberTwo; } MYSTRUCT; The way I understand this, tagMyStruct is the new data type and MYSTRUCT is a variable that is created right there. At another place, this was used like this: MYSTRUCT *pStruct = new MYSTRUCT; and it compiled fine with Visual Studio 2010. How is that valid C++? I thought MYSTRUCT was a variable and not a type? 回答1: No. tagMyStruct is the name of the

问题 This question already has answers here : Learning Resources on Parsers, Interpreters, and Compilers [closed] (12 answers) Closed 5 years ago . Summary for the impatient: I'm searching for good references on generating code for common language constructs but not parsing. I am interested in programming languages and try to read the literature as much as possible. But most of them covers the topic in a functional and theoretical perspective that, I find them hard to understand let alone

问题 This question already has answers here : Learning Resources on Parsers, Interpreters, and Compilers [closed] (12 answers) Closed 5 years ago . Summary for the impatient: I'm searching for good references on generating code for common language constructs but not parsing. I am interested in programming languages and try to read the literature as much as possible. But most of them covers the topic in a functional and theoretical perspective that, I find them hard to understand let alone