A Functional Shell That Dynamically Combines Compiled Code

We present a new shell that provides the full basic functionality of a strongly typed lazy functional language, including overloading. The shell can be used for manipulating files, applications, data and processes at the command line. The shell does type checking and only executes well-typed expressions. Files are typed, and applications are simply files with a function type. The shell executes a command line by combining existing code of functions on disk. We use the hybrid static/dynamic type system of Clean to do type checking/inference. Its dynamic linker is used to store and retrieve any expression (both data and code) with its type on disk. Our shell combines the advantages of interpreters (direct response) and compilers (statically typed, fast code). Applications (compiled functions) can be used, in a type safe way, in the shell, and functions defined in the shell can be used by any compiled application.