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Everything about Metaclass

Class that describes common behavior for classes

In object-oriented programming, a metaclass is a class whose syntactic definitions are used for the syntactic definition of the classes themselves. Unlike ordinary classes, which define the behaviors of objects, metaclasses specify the behaviors of classes and their instances. Not all object-oriented programming languages support the concept of metaclasses. For those that do, the extent of control metaclasses have over class behaviors varies. Metaclasses are often implemented by treating classes as first-class citizens, making a metaclass an object that creates and manages these classes. Each programming language adheres to its own metaobject protocol, which are the rules that determine interactions among objects, classes, and metaclasses. Metaclasses are utilized to automate code generation and to enhance framework development. Wikipedia →

🧭 Start here: a 6-step reading path

  1. Read the overview: MetaclassA 5-minute orientation
  2. Pick up a classic book: Smalltalk-80The most-reprinted book on the subject
  3. Read the landmark paper: Materialization and its metaclass implementationCited 23 times
  4. Go sideways: Type introspectionA closely related topic
  5. Go sideways: Class (programming)A closely related topic

đź“– Definitions

Noun A class that serves as a template for other classes rather than objects.

🗂️ The subject at a glance

  1. Python example
  2. In Smalltalk-80
  3. In Ruby
  4. In Objective-C
  5. C++ proposal
  6. Support in languages and tools

🏆 Landmark papers (most cited)

đź“š Books worth reading

Ranked by number of editions on Open Library, a rough measure of how lasting a book is.

đź”— Related topics