Smalltalk
Smalltalk is an object-oriented, dynamically typed reflective programming language.
Smalltalk environments were often the first to develop what are now common object-oriented software design patterns. One of the most popular is the model–view–controller (MVC) pattern for user interface design. The MVC pattern enables developers to have multiple consistent views of the same underlying data. It's ideal for software development environments, where there are various views (e.g., entity-relation, dataflow, object model, etc.) of the same underlying specification.
As in other object-oriented languages, the central concept in Smalltalk-80 is that of an object. An object is always an instance of a class. Classes are "blueprints" that describe the properties and behavior of their instances.
A Smalltalk object can do exactly three things:
- Hold state (references to other objects).
- Receive a message from itself or another object.
- In the course of processing a message, send messages to itself or another object.
(...) messaging is the most important concept in Smalltalk: "The big idea is 'messaging' (...) Smalltalk is a "pure" object-oriented programming language
The message is the most fundamental language construct in Smalltalk. Even control structures are implemented as message sends. Smalltalk adopts by default a synchronous, single dynamic message dispatch strategy (as contrasted to the asynchronous, multiple dispatch strategy adopted by some other object-oriented languages).
Smalltalk is a fully object oriented language.
The most important and consistent ideas in the language are that:
- (1) there are objects
- (2) send messages to objects
- (3) get back an object as the result