Zef Programming Language

Zef is a dynamically typed programming language that combines object-oriented and functional paradigms. It was developed primarily to demonstrate language implementation techniques.

Its type system treats all values as objects descending from a base Object type. Variables and fields carry no static types. Integers and floating-point numbers are both represented as 64-bit objects, with null defined as a synonym for 0, false as a synonym for 0, and true as a synonym for 1. The class system follows a Ruby-like model in which fields remain private to their instance unless explicitly exposed through accessors. Classes and functions support arbitrary nesting, which automatically creates closures; member functions inside a nested class can therefore access local variables from an enclosing function.

Zef deliberately omits certain dynamic-language mechanisms to maintain a cleaner design. It contains no eval operation and provides no monkey-patching facilities. The load primitive can read and execute a source file, yet the loaded code runs inside its own isolated scope. Classes must statically declare their fields, preventing the addition of new fields at runtime or the mutation of an object's type after creation. Packages offer a namespace mechanism that allows classes and functions to be nested inside them and made globally visible to code that imports or names the package. Memory management relies on automatic garbage collection, so allocated objects are reclaimed without explicit deallocation.

The language serves as an educational and demonstrative tool for those studying how programming languages are built. It is delivered as a standalone implementation whose source and documentation appear on its project site. No pricing or licensing details are stated in the available material.