Aug 31, 2008 · A closure is a function and its scope assigned to (or used as) a variable. Thus, the name closure: the scope and the function is enclosed and used just like any other entity. In depth Wikipedia style explanation. According to Wikipedia, a closure is: Techniques for implementing lexically scoped name binding in languages with first-class functions.

Apr 21, 2015 · A closure is basically just a different way of looking at an object. An object is data that has one or more functions bound to it. A closure is a function that has one or more variables bound to it. The two are basically identical, at an implementation level at least. The real difference is in where they come from.

Aug 20, 2009 · A closure is just one function that has access to a bunch of state, but a class has many methods which share access to the same state. Many languages (e.g. Java, Python, etc.) have local classes, which can capture variables from surrounding scope just like a closure; so they are strictly more general than closures. –

Jun 5, 2015 · Unfortunately, those courses just present the closure; they do not explain why the code solution is written as a closure. An example of a real world programming problem that might trigger my brain to say, "aha, I should write a closure for this", would be more informative than a theoretical discussion. There is no shortage of theoretical ...

Jan 6, 2023 · And a closure, quoting Scott's Programming Language Pragmatics is explained as: … creating an explicit representation of a referencing environment (generally the one in which the subroutine would execute if called at the present time) and bundling it together with a reference to the subroutine … is referred to as a closure.

The local variable x persists through the closure even after foo terminated and can be incremented through calls of the returned anonymous function. val counter = foo() print counter() // Returns 2 print counter() // Return 3 Note that's just Ruby in which block and closure are treated similarly since what Ruby calls block is a closure:

Some details: Scope: The scope of a closure is the data and members that can be accessed within it. Returning from a closure: Closures often use a callback mechanism to execute and return from itself. Arguments: If the closure needs to take only 1 param, Groovy and other langs provide a default name: "it", to make coding quicker.

Apr 21, 2015 · However, I was not able to find references of how to formally describe function closures in computer programming. I must admit I have searched in only a handful of programming books. Without any success. What I really need is the formal, precise and maybe mathematical definition of the concept of function closure in computer programming.

Dec 30, 2015 · Assuming you mean within the context of computer science... A closure is a first class function which captures the lexical bindings of free variables in its defining environment. Once it has captured the lexical bindings the function becomes a closure because it "closes over" those variables. Note this means closures only exist at run time.

Jul 24, 2013 · In programming languages, a closure (also lexical closure or function closure) is a function or reference to a function together with a referencing environment—a table storing a reference to each of the non-local variables (also called free variables or upvalues) of that function.[1] A closure—unlike a plain function pointer—allows a ...