anonymous-function

Given a block like this: var foo = {"regexp":/^http:\/\//, "fun":function(){}, } What is a proper way to store it in JSON? You have to store the RegExp as a string in the JSON object. You can then construct a RegExp object from the string: // JSON Object (can be an imported file, of course) // Store RegExp pattern as a string // Double backslashes are required to put literal \ characters in the string var jsonObject = { "regex": "^http:\\/\\/" }; function fun(url) { var regexp = new RegExp(jsonObject.regex, 'i'); var match; // You can do either: match = url.match(regexp); // Or (useful for

I'm new-ish to JavaScript. I understand many of the concepts of the language, I've been reading up on the prototype inheritance model, and I'm whetting my whistle with more and more interactive front-end stuff. It's an interesting language, but I'm always a bit turned off by the callback spaghetti that is typical of many non-trivial interaction models. Something that has always seemed strange to me is that in spite of the readability nightmare that is a nest of JavaScript nested callbacks, the one thing that I very rarely see in many examples and tutorials is the use of predefined named

How does Clojure determine how many arguments an anonymous function (created with the #... notation) expect? user=> (#(identity [2]) 14) java.lang.IllegalArgumentException: Wrong number of args (1) passed to: user$eval3745$fn (NO_SOURCE_FILE:0) #(println "Hello, world!") -> no arguments #(println (str "Hello, " % "!")) -> 1 argument ( % is a synonym for %1 ) #(println (str %1 ", " %2 "!")) -> 2 arguments and so on. Note that you do not have to use all %n s, the number of arguments expected is defined by the highest n. So #(println (str "Hello, " %2)) still expects two arguments. You can also

The PHP manual states It is not possible to use $this from anonymous function before PHP 5.4.0 on the anonymous functions page . But I have found I can make it work by assigning $this to a variable and passing the variable to a use statement at the function definition. $CI = $this; $callback = function () use ($CI) { $CI->public_method(); }; Is this a good practice? Is there a better way to access $this inside an anonymous function using PHP 5.3? It will fail when you try to call a protected or private method on it, because using it that way counts as calling from the outside. There is no way

Possible Duplicate: How can I pre-set arguments in JavaScript function call? (Partial Function Application) I need to able to pass a reference to a function with a given set of parameters . Here is an example of passing a reference without parameters: var f = function () { //Some logic here... }; var fr = f; //Here I am passing a reference to function 'f', without parameters fr(); //the 'f' function is invoked, without parameters Now what I need to do is pass the same f function, but this time I would need to pass parameters to the reference. Now, I can do it with an anonymous function and

Specifically, I want to write this: public Func<IList<T>, T> SelectElement = list => list.First(); But I get a syntax error at T . Can't I have a generic anonymous method? Nope, sorry. That would require generic fields or generic properties, which are not features that C# supports. The best you can do is make a generic method that introduces T: public Func<IList<T>, T> SelectionMethod<T>() { return list => list.First(); } And now you can say: Func<IList<int>, int> selectInts = SelectionMethod<int>(); Of course you can, but T must be known: class Foo<T> { public Func<IList<T>, T>