RUSty CALculator scripting language learning project
Try it now on your browser! https://msakuta.github.io/ruscal/
This repo is the implementation of the example script used in my book: Rustで作るプログラミング言語 (Japanese).
This is a sister project of rustack, a custom programming language compiler / interpreter.
Ruscal is a stack-based scripting language specifically designed for learning creating a programming language. As such, its target is not a feature-rich next-gen language. It is a boring language that intends to help the reader to learn how to make his or her own language.
The process of the language design is split into steps.
Each step has an entry in examples directory.
Each step works as an independent program.
Use --example switch of cargo to run them.
For example:
cargo r --example 00-match
Although its target is not a useful language, it has few notable features:
f64,i64andstrprimitive types (which are what you would expect)- Rust-like syntax and a parser (implemented with nom)
- Basic control flow structures by
ifandforstatements - Variable declarations with type annotations
- Static type checking on function arguments, return types and expressions
- Stack-based bytecode interpreter and compiler
- Coroutines and generators
You can also build a wasm package and run the interpreter on the browser.
cd wasm
npm i
npm run build
To launch the application, you can use npx
cd dist
npx serve
and browse http://localhost:5000.
There are number of example scripts in scripts directory, but most of them require specific step of the interpreter to run. Those target step numbers are indicated by prefixes of the file names.
The standard script file extension is .rscl, because there is already a language called Rascal and they took .rsc.
For example, this is a Mandelbrot set in ASCII art, rendered with 31-mandel.rscl:
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