README.md

simple lisplike shell

How to use

1. install system dependencies
2. clone repo
3. run yarn oder npm install from within the repo to install js dependencies
4. run yarn run start/npm start to compile the grammar and run the interpreter OR
5. just run the interpreter with node index.js

System Dependencies:

• git
• node js
• yarn/npm

How it works

• all programs are expressions
• all expressions are withing round brackets () excepting:
  • there are implicit round brackets () around the outer expression
• expressions get parsed into an abstrace syntax tree (AST)
  • currently 2 types of nodes (expression, assignment) and 1 atom (string)
• the AST gets interpreted by a recursive function

What works

• expressions/return values/outputs
  • > echo hi // => hi
• nested expressions
  • > echo (echo hi) // => hi
• > x = echo hi // global symbol binding (aka setting variables); lazy evaluated
  • > x // calling nested expressions
• piping, after a fashion; currently bash does the piping for us ;)
• extending the language by writing js functions

What doesn't (yet)

• piping inside the language (currently bash does it)
• local variables/context/this
• symbols with arguments (aka functions with arguments)
  • > f x = echo (x)
  • > + x y = echo (x)+(y) | bc
• extending the language with macros (functions on the raw ast)