The Programming Languages Zoo

boa

A simple object-oriented language with eager evaluation, first-class functions, and dynamic types. It is based on a notion of objects as extensible records. There are no classes.

The language has the following features:

• integers with arithmetical operations *, +, -, /
• booleans with conditional statements and comparison =, < of integers
• first-class functions
• mutable objects as extensible records, i.e., an object obj1 can be extended by object obj2 to form the combined object obj1 with obj2.

An interesting feature of the language is that, since “everything is an object”, a value may behave simultaneously as an integer, boolean, function, and a record. See examples below.

Example

The file example.boa shows basic examples and implements recursion and lists using objects.