RPythonin

RPythonin is a programming language that is a restricted subset of Python. It is designed to be amenable to static analysis and compilation, which allows for the creation of highly optimized code. The primary goal of RPythonin is to enable the development of high-performance interpreters and compilers for other programming languages.

The language is called "restricted" because it deliberately disallows certain dynamic features of standard Python that make static analysis difficult. For instance, RPythonin does not allow for arbitrary object mutation or dynamic type changes. This strictness is what allows RPythonin to be translated into C code, which can then be compiled into highly efficient machine code.

The most well-known application of RPythonin is the PyPy project, an alternative implementation of the Python programming language. PyPy uses RPythonin to implement its interpreter, which can then be translated into C. This translation process results in a Python interpreter that is often significantly faster than the standard CPython implementation. Beyond PyPy, RPythonin has also been used to implement interpreters for other languages.

The development of RPythonin is closely tied to the PyPy project, and its features are often driven by the needs of building a fast and robust Python interpreter. While it shares much of its syntax with Python, the restrictions are key to its performance advantages.