Go Flashcards
Error
Indicates abnormal state; should be handled.
Panic
Indicates unrecoverable conditions; should typically abort the program.
Channel usage
passing ownership of data,
distributing units of work,
communicating async results
Mutex
caches,
state
sync.WaitGroup
Allows co-operating goroutines to collectively wait for a threshold event before proceeding independently again. This is useful typically in two cases.
Firstly, when ‘cleaning up’, a sync.WaitGroup can be used to ensure that all goroutines - including the main one - wait before all terminating cleanly.
The second more general case is of a cyclic algorithm that involves a set of goroutines that all work independently for a while, then all wait on a barrier, before proceeding independently again. This pattern might be repeated many times. Data might be exchanged at the barrier event. This strategy is the basis of Bulk Synchronous Parallelism (BSP).
Method sets
Method Sets: A type may have a method set associated with it. The method set of an interface type is its interface. The method set of any other named type T consists of all methods with receiver type T. The method set of the corresponding pointer type *T is the set of all methods with receiver *T or T (that is, it also contains the method set of T). Any other type has an empty method set. In a method set, each method must have a unique name.
Calls: A method call x.m() is valid if the method set of (the type of) x contains m and the argument list can be assigned to the parameter list of m. If x is addressable and &x’s method set contains m, x.m() is shorthand for (&x).m().
It is legal to call a pointer-valued method on anything that is already a pointer or whose address can be taken (as is the case in the above example). It is legal to call a value method on anything which is a value or whose value can be dereferenced (as is the case with any pointer; this case is specified explicitly in the spec).
