Primer

0.0.2

Assign/Partial/ReadOnly/Proxy/Locks in Swift
alexdrone/Primer

What's New

Primer 0.0.2

2021-10-31T10:15:16Z

Primer Swift

Assign

This function is used to copy the values of all enumerable own properties from one or more source struct to a target struct. If the argument is a reference type the same refence is returned.

public func assign<T>(_ value: T, changes: (inout T) -> Void) -> T

Partial

Constructs a type with all properties of T set to optional. This utility will return a type that represents all subsets of a given type.

The wrapped type can be then constructed at referred time by calling the build() method. The instance can be later on changed with the merge(inout _:) method.

struct Todo { var title: String; var description: String } 
var partial = Partial { .success(Todo(
 title: $0.get(\Todo.title, default: "Untitled"),   
 description: $0.get(\Todo.description, default: "No description"))) 
} 
partial.title = "A Title" 
partial.description = "A Description" 
var todo = try! partial.build().get() 
partial.description = "Another Descrition" 
todo = partial.merge(&todo) 

ReadOnly

Constructs a type with all properties of T set to readonly, meaning the properties of the constructed type cannot be reassigned.

Note A read-only object can propagate change events if the wrapped type ia an ObservableObject by calling propagateObservableObject() at construction time.

struct Todo { var title: String; var description: String }
let todo = Todo(title: "A Title", description: "A Description")
let readOnlyTodo = ReadOnly(todo)
readOnlyTodo.title // "A title"

ObservableProxy

Creates an observable Proxy for the object passed as argument (with granularity at the property level).

struct Todo { var title: String; var description: String }
let todo = Todo(title: "A Title", description: "A Description")
let proxy = Proxy(todo)
proxy.propertyDidChange.sink {
  if $0.match(keyPath: \.title) {
    ...
  }
}
proxy.title = "New Title"

Concurrency

This package offer a variety of different lock implementations:

  • Mutex: enforces limits on access to a resource when there are many threads of execution.
  • UnfairLock: low-level lock that allows waiters to block efficiently on contention.
  • ReadersWriterLock: readers-writer lock provided by the platform implementation of the POSIX Threads standard.

Property wrappers to work with any of the locks above or any NSLocking compliant lock:

  • @LockAtomic<L: Locking>
  • @SyncDispatchQueueAtomic
  • @ReadersWriterAtomic

The package also includes LockfreeAtomic: fine-grained atomic operations allowing for Lockfree concurrent programming. Each atomic operation is indivisible with regards to any other atomic operation that involves the same object.

Description

  • Swift Tools 5.1.0
View More Packages from this Author

Dependencies

Last updated: Sun Sep 11 2022 04:00:14 GMT-0500 (GMT-05:00)