Typescript implementation of SNL compiler front-end

SNL (Small Nested Language) is a pascal-like procedural language used for teaching purpose.

It's a suitable language for a toy compiler as it is very simple (and therefore incapable).

Check docs/snl.bnf and sample snl code in sample folder to find out more about this language.

Features

• Lexical analysis
• Syntax analysis
  • Predict set and table generated on the fly
  • Recursive descent parsing
  • LL(1) parsing
• Semantic analysis
• Command line interface

Usage

0. You should have node and npm (or pnpm, yarn) in your computer and know the basic usage. (This project is using pnpm, you can also choose npm or yarn, doesn't matter too much)
1. Clone this repo and enter the directory
2. Run pnpm install (or npm install)
3. Run pnpm build (or npm run build) to build the project
4. pnpm snlc <file> -- <flags> (or npm run snlc <file> -- <flags>)
   • --set show predict sets
   • --table show predict table
   • --token show token list
   • --ast show AST
   • --ll use LL(1) parser as parser, the default is recursive descent parser
   • If the file is in sample folder, then you can omit full path and just type file name for convenience
   • For example, pnpm snlc 1 -- --ast will compile sample/1.snl and print AST