A Closure-based State implementation in Swift.
tl;dr Recently the Harvard Business Review ran an article on how readers could prepare for difficult business situations, using the analogy of coaches preparing their teams for different eventualities by simulating those eventualities on the practice field. There’s lessons to be learned here for both programming and speaking.
Let’s talk a bit about the various pattern implementations, the languages in which they are being written, and what to “get” out of them.
A Closure-based State implementation in F#.
A Closure-based State implementation in Java.
A Closure-based State implementation in C#.
tl;dr Patterns, 20 Years Later: With the prevalance of libraries and tools that can peer past access controls (such as Reflection on the JVM and CLR, or the Mirrors facility in Swift), trying to encapsulate private details away from prying eyes can be increasingly difficult. Other languages lack access controls entirely, or the concept of objects. In any of these languages that offer closures, we can hold state within a closure yet outside of the object, rendering it almost entirely inaccessible to outside parties.
tl;dr Patterns, 20 Years Later: A Constructor Function is a function designed specifically to construct instances of entities (typically objects, although in languages which do not support objects as native types, this will typically be something that masquerades as an object). It is often seen as a variation on a Factory Method, though there is enough variation on the intent that it is worth calling this out as a standalone pattern.