definition

What is managed or unmanaged code in programming?

由 不想你离开。 提交于 2019-11-26 02:41:34
问题 I am using a specific command in in my C# code, which works well. However, it is said to misbehave in \"unmanaged\" code. What is managed or unmanaged code? 回答1: Here is some text from MSDN about unmanaged code. Some library code needs to call into unmanaged code (for example, native code APIs, such as Win32). Because this means going outside the security perimeter for managed code, due caution is required. Here is some other complimentary explication about Managed code: Code that is executed

What is a Y-combinator? [closed]

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-11-26 02:25:49
问题 A Y-combinator is a computer science concept from the “functional” side of things. Most programmers don\'t know much at all about combinators, if they\'ve even heard about them. What is a Y-combinator? How do combinators work? What are they good for? Are they useful in procedural languages? 回答1: If you're ready for a long read, Mike Vanier has a great explanation. Long story short, it allows you to implement recursion in a language that doesn't necessarily support it natively. 回答2: A Y

What is Weak Head Normal Form?

由 |▌冷眼眸甩不掉的悲伤 提交于 2019-11-26 01:34:38
问题 What does Weak Head Normal Form (WHNF) mean? What does Head Normal form (HNF) and Normal Form (NF) mean? Real World Haskell states: The familiar seq function evaluates an expression to what we call head normal form (abbreviated HNF). It stops once it reaches the outermost constructor (the “head”). This is distinct from normal form (NF), in which an expression is completely evaluated. You will also hear Haskell programmers refer to weak head normal form (WHNF). For normal data, weak head

Easy to understand definition of “asynchronous event”? [closed]

由 穿精又带淫゛_ 提交于 2019-11-26 01:13:18
问题 I\'ve encountered this term a lot, and even after Googling, still can\'t understand what exactly it means. Is there some easy-to-understand (ideally with examples) definition of what an asynchronous event is that someone can provide? Thanks! 回答1: Non programming example: Synchronous You want a pizza for dinner and you are out of the frozen kind. So you have to stop playing WOW which upsets your guild. You go to the kitchen, make the dough, cover it with sauce, add the cheese, and smother it

How to find where a method is defined at runtime?

由 冷暖自知 提交于 2019-11-26 00:45:17
问题 We recently had a problem where, after a series of commits had occurred, a backend process failed to run. Now, we were good little boys and girls and ran rake test after every check-in but, due to some oddities in Rails\' library loading, it only occurred when we ran it directly from Mongrel in production mode. I tracked the bug down and it was due to a new Rails gem overwriting a method in the String class in a way that broke one narrow use in the runtime Rails code. Anyway, long story short

What is the difference between currying and partial application?

由 北城以北 提交于 2019-11-26 00:34:49
问题 I quite often see on the Internet various complaints that other peoples examples of currying are not currying, but are actually just partial application. I\'ve not found a decent explanation of what partial application is, or how it differs from currying. There seems to be a general confusion, with equivalent examples being described as currying in some places, and partial application in others. Could someone provide me with a definition of both terms, and details of how they differ? 回答1:

What's the difference between faking, mocking, and stubbing?

由 隐身守侯 提交于 2019-11-26 00:29:21
问题 I know how I use these terms, but I\'m wondering if there are accepted definitions for faking , mocking , and stubbing for unit tests? How do you define these for your tests? Describe situations where you might use each. Here is how I use them: Fake : a class that implements an interface but contains fixed data and no logic. Simply returns \"good\" or \"bad\" data depending on the implementation. Mock : a class that implements an interface and allows the ability to dynamically set the values

What is an idempotent operation?

由 我怕爱的太早我们不能终老 提交于 2019-11-25 23:59:43
问题 What is an idempotent operation? 回答1: In computing, an idempotent operation is one that has no additional effect if it is called more than once with the same input parameters. For example, removing an item from a set can be considered an idempotent operation on the set. In mathematics, an idempotent operation is one where f(f(x)) = f(x) . For example, the abs() function is idempotent because abs(abs(x)) = abs(x) for all x . These slightly different definitions can be reconciled by considering

What's the difference between unit, functional, acceptance, and integration tests? [closed]

由 ≡放荡痞女 提交于 2019-11-25 22:59:35
What is the difference between unit, functional, acceptance, and integration testing (and any other types of tests that I failed to mention)? Depending on where you look, you'll get slightly different answers. I've read about the subject a lot, and here's my distillation; again, these are slightly wooly and others may disagree. Unit Tests Tests the smallest unit of functionality, typically a method/function (e.g. given a class with a particular state, calling x method on the class should cause y to happen). Unit tests should be focussed on one particular feature (e.g., calling the pop method

What is the difference between a definition and a declaration?

由 徘徊边缘 提交于 2019-11-25 22:51:37
问题 The meaning of both eludes me. 回答1: A declaration introduces an identifier and describes its type, be it a type, object, or function. A declaration is what the compiler needs to accept references to that identifier. These are declarations: extern int bar; extern int g(int, int); double f(int, double); // extern can be omitted for function declarations class foo; // no extern allowed for type declarations A definition actually instantiates/implements this identifier. It's what the linker needs
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