AlexScript

AlexScript (which is a misnomer; the language will soon be renamed since it's not actually a scripting language) is a programming language designed to have a functional feel and very high-level ergonomics while maintaining speed using strictly-controlled, deterministic memory management.

Tools

This repository contains the following tools:

• axc, the AlexScript compiler. This can be used as a binary with a fairly standard compiler CLI, or as a library for use in other programs.

The following tools do not exist yet, but are planned:

• axci, the interactive AlexScript interpreter.
• axcd, the Language Server Protocol (LSP) server for AlexScript code support in editors, supporting definition peeking and lookup, renaming variables and modules, etc.
• axfmt, the standard formatter for AlexScript code; all AlexScript code used in this repository must be formatted with axfmt, and its use is recommended for other projects.
• axdoc, the documentation generator.
• alexscript-mode, an Emacs mode for editing AlexScript code, supporting syntax highlighting, automatic indentation, some basic keybindings for common tasks, Emacs-side LSP integration for communicating with acxd, and a collection of yasnippet snippets for inserting common AlexScript constructs.
• alexscript-vsc, Visual Studio Code plugins and tools for editing AlexScript code.
• alexscript-vim, tools and configuration files for optimizing Vim and Neovim for editing AlexScript code.

Language features

The language is mostly influenced by Rust and Haskell: it has strict safety requirements and borrow-checked memory management like that of Rust, but its syntax and type system are similar to those of Haskell.

Some features the language will most likely have:

• All functions are pure by default; side effects are chained together using an IO monad.
• Despite the language's purity, expressions will be strictly evaluated to provide more programmer control.
• Different monads represent different levels of safety, and can be converted using functions marked as UNSAFE. The intention is that code can be audited by manually checking that all the UNSAFE transformations are sound, and code that contains no UNSAFE function calls are guaranteed to satisfy varying definitions of soundness:
  • The IO monad represents computations that might have side effects on the real world. If a computation of type IO is known by the programmer to not have side effects on the real world, then it can be converted to a pure computation using the standard library function UNSAFE_assertPure : IO a -> a.
  • The MemoryUnsafe monad represents computations that might read from or write to memory that is not allocated correctly: for example, readPtr, which reads from a raw pointer, is of type MemoryUnsafe a because the pointer is not known to be valid. If a computation has been confirmed to be safe by the programmer, it can be converted to an IO computation using UNSAFE_assertMemorySafe : MemoryUnsafe a -> IO a.
  • Further safety monads may be added in the future.

Compilation