Classlike

Classlike is a term used in programming language design and static analysis to describe constructs that resemble classes in object-oriented programming. A classlike construct typically groups data and behavior and participates in polymorphism or type hierarchies, but may not be a concrete class in the language’s syntax or runtime model. The exact definition of classlike varies by language and tool, but it commonly includes classes, interfaces, traits, enums, and sometimes records or mixins.

In PHP tooling, for example, classlike is a broad category that encompasses all user-defined types that can be referenced by a type name, including classes, interfaces, traits, and enums. Static analyzers treat classlikes as a single category for purposes such as type resolution, instantiation rules, and visibility checks. A classlike value may be instantiable (as a class), abstract (cannot be instantiated), or non-instantiable (interface, trait, or enum in some languages).

Important distinctions include that a class is typically instantiable, an interface defines a contract without a constructor, a trait provides reusable methods that must be used within a class, and an enum defines a fixed set of values. Some languages also include records or structures with associated methods under the classlike umbrella. The concept is useful for code documentation, tooling, and type analysis, allowing generic reasoning about types that behave like classes without requiring language-specific keywords.

Use and relevance: classlike concepts help developers understand and reason about code structure, enable cross-language tooling, and support analyses that generalize over multiple kinds of object-oriented definitions.