convenience-methods

Is there a convenient and functional ( with-... -like) way of temporary modifying environment variables when using shell-comand or start-process ? Thanks in advance, Per server-with-environment looks promising. server-with-environment is a Lisp macro in `server.el'. (server-with-environment ENV VARS &rest BODY) Evaluate BODY with environment variables VARS set to those in ENV. The environment variables are then restored to their previous values. VARS should be a list of strings. ENV should be in the same format as `process-environment'. process-environment is a List of overridden environment

In most languages I have dealt with, one something is called a convenience method, it means that the method does some small task that gets done very frequently, and therefore it is more convenient to use said method. In Objective-C does this definition hold true? Or is it generally only used to describe class methods that return a prebuilt object? ex. [NSString stringWithContentsOfFile:...] Is this just a preference thing, or are there some hard and fast definition for these terms? Cheers, Stefan What you are talking about is actually more specifically a "convenience constructor" in Objective

I have this function: extension UIImage { static func from(layer: CALayer) -> UIImage? { UIGraphicsBeginImageContext(layer.frame.size) layer.render(in: UIGraphicsGetCurrentContext()!) let outputImage: UIImage? = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return outputImage } } How can I change it into like this? extension UIImage { convenience init(layer: CALayer) { self.init(); UIGraphicsBeginImageContext(layer.frame.size) layer.render(in: UIGraphicsGetCurrentContext()!) let outputImage: UIImage? = UIGraphicsGetImageFromCurrentImageContext()

Assume you have a Singleton Constants class, instance of which you'd like to use throughout your application. In someClass , therefore we can reference [Constants instance] someCleverConstant]; Typing this gets old really quick and it would be nice to get a shortcut to the instance. In someClass , we can declare @property (nonatomic, weak, readonly) Constants *constants; And a getter to the instance -(Constants*) constants { if (constants == nil) constants = [Constants instance]; return constants; } This way in someClass, therefore we can reference constants.someCleverConstant; instead A few