Simple way to get wrapper class type in Java
Apache Commons Lang has a utility method to do this (ClassUtils.primitiveToWrapper()), which will be just as ugly under the covers, but at least you can pretend it’s nice.
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How do I wrap a function in Javascript?
Personally instead of polluting builtin objects I would go with a decorator technique: var makeSafe = function(fn){ return function(){ try{ return fn.apply(this, arguments); }catch(ex){ ErrorHandler.Exception(ex); } }; }; You can use it like that: function fnOriginal(a){ console.log(1/a); }; var fn2 = makeSafe(fnOriginal); fn2(1); fn2(0); fn2(“abracadabra!”); var obj = { method1: function(x){ /* do something */ … Read more
Exposing `defaultdict` as a regular `dict`
defaultdict docs say for default_factory: If the default_factory attribute is None, this raises a KeyError exception with the key as argument. What if you just set your defaultdict’s default_factory to None? E.g., >>> d = defaultdict(int) >>> d[‘a’] += 1 >>> d defaultdict(<type ‘int’>, {‘a’: 1}) >>> d.default_factory = None >>> d[‘b’] += 2 Traceback … Read more
What’s the relative order with which Windows search for executable files in PATH?
See the command search sequence on Microsoft Docs The PATH and PATHEXT environmental variables each provide an element of the search sequence: PATH is the ordered list of directories “where” to look, and PATHEXT is the ordered list of file extensions (“what“) to look for (in case the extension isn’t explicitly provided on the command … Read more
How to convert Integer[] to int[] array in Java?
You can use Stream APIs of Java 8 int[] intArray = Arrays.stream(array).mapToInt(Integer::intValue).toArray();
Creating simple c++.net wrapper. Step-by-step
http://www.codeproject.com/KB/mcpp/quickcppcli.aspx#A8 This is general direction. You need to create C++/CLI Class Library project, add .NET class to it (StudentWrapper in this sample), create unmanaged class instance as managed class member, and wrap every unmanaged class function. Unmanaged library is added to C++/CLI project using linker dependencies list, and not as reference. In the Project – … Read more
How to safely wrap `console.log`?
The problem with wrappers is that they will obfuscate file name and line number of the source of the log message. Simple IE7 and below shim that preserves Line Numbering for other browsers: /* console shim*/ (function () { var f = function () {}; if (!window.console) { window.console = { log:f, info:f, warn:f, debug:f, … Read more
What is the meaning of a C++ Wrapper Class?
A “wrapper class” is a de facto term meaning a class that “wraps around” a resource; i.e, that manages the resource. When people write a wrapper, then, they are doing something like this: class int_ptr_wrapper { public: int_ptr_wrapper(int value = 0) : mInt(new int(value)) {} // note! needs copy-constructor and copy-assignment operator! ~int_ptr_wrapper() { delete … Read more
How to test an internal class in a class library?
In .NET, you can use the InternalsVisibleToAttribute in your class library to make your internal types visible to your unit test project. That way, you can keep your class internal and still use it from other assemblies that you give access. You use it like this: [assembly:InternalsVisibleTo(“NameOfYourUnitTestProject”)]
How many objects are created by using the Integer wrapper class?
The answer, surprisingly, is zero. All the Integers from -128 to +127 are pre-computed by the JVM. Your code creates references to these existing objects.