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When do you use defer in a program?
Defer is used in places where a function call should be executed irrespective of the code flow. Let’s understand this with the example of a program which makes use of WaitGroup. We will first write the program without using defer and then we will modify it to use defer and understand how useful defer is.
When to use the defer attribute in JavaScript?
If you have any noncritical JavaScript file, or any code that depends on the DOM being rendered to run, load it in the head with the defer attribute. This will result in the best performance on most browsers. That is, of course, unless your entire document is less than 14kb minified and gzipped. In that case, you’re better off inlining everything.
When to evaluate the arguments of a deferred function?
The arguments of a deferred function are evaluated when the defer statement is executed and not when the actual function call is done. Let’s understand this by means of an example.
How to override package deferral in Emacs?
You can override package deferral with the :demand keyword. Thus, even if you use :bind, using :demand will force loading to occur immediately and not establish an autoload for the bound key. Another feature of use-package is that it always loads every file that it can when .emacs is being byte-compiled.
How to execute code before a package is loaded?
Use the :init keyword to execute code before a package is loaded. It accepts one or more forms, up to the next keyword: Similarly, :config can be used to execute code after a package is loaded. In cases where loading is done lazily (see more about autoloading below), this execution is deferred until after the autoload occurs:
How to use use-package in package.el?
You can use use-package to load packages from ELPA with package.el. This is particularly useful if you share your .emacs among several machines; the relevant packages are downloaded automatically once declared in your .emacs . The :ensure keyword causes the package (s) to be installed automatically if not already present on your system:
What happens to Printa ( a ) in defer statement?
From the above output it can be understood that although the value of a changes to 10 after the defer statement is executed, the actual deferred function call printA (a) still prints 5. When a function has multiple defer calls, they are pushed on to a stack and executed in Last In First Out (LIFO) order.