hg graft

hg graft: apply a commit from another branch to current branch

hg rebase -d master: apply your current branch with master branch changes. If a file is in master, but not on your current brach. That means your current branch delete the file.

Advertisements

protocol

https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/WorkingwithProtocols/WorkingwithProtocols.html

A class interface declares the methods and properties associated with that class. A protocol, by contrast, is used to declare methods and properties that are independent of any specific class.

By default, all methods declared in a protocol are required methods. This means that any class that conforms to the protocol must implement those methods.

It’s also possible to specify optional methods in a protocol. These are methods that a class can implement only if it needs to.