Project Emerald

Overview

An educational attempt to invent a programming language called Emerald. This repository will include everything related this. The main part of this is the Emerald compiler. This may expand to include tooling also.

Language Overview

Support for features is slow as this is an educational project. You can see the language grammar in the docs folder of this repo. Currently, Emerald supports the following programming constructs:

• Single and Multiline comments (using # and #*...*# respectively)
• Integer data types ONLY
• Variable assignment and reassignment (assignment using let)
• Basic mathematical expressions using +, -, *, /
• If/else-if/else statements (if (...) {} else if (...) {} else {})

Features in progress

• While loop (while (...) {})
• Relational and equality expressions (==, !=, <, >, <=, >=)

Up-and-Coming Features

• For loop
• Basic Functions
• Variable assignment in if/while expression (if (let a = ...) {} etc)
• External code
• and more...

Sample

There is a full sample in the

Tech Stack & Dependencies

The compiler itself will start in C++ (in the far-flung future maybe we will build the compiler in Emerald but this is a far off dream for now), and will use various homebrew C++ libraries of my own for certain aspects. The main thing here is that we most of the compiler sections will be written from scratch not using any lexing or parsing frameworks.

Currently, this supports linux only and uses nasm and ld to assemble and link the final programs. The compiler uses the CMake build system.

Compiling a file

To compile a simple Emerald file, launch a WSL terminal and simply run

Emerald <path/to/emd file> -out test

here the argument passed to -out will be the name of the executable. You can then run your program with the command

./test; echo $?

which will also print out the error code.

Compiler Development

Checkout

To build the compiler checkout the source code use

git clone --recursive https://github.com/pmann84/Emerald.git

to pull down the submodule dependencies. If you forget you can use

git clone https://github.com/pmann84/Emerald.git
cd Emerald
git submodule update --init --recursive

Then to configure and build use the provided CMake files in the root of the project.

Setting up for Windows

I use CLion on Windows to develop this so far, but since I'm only supporting Linux you need to setup an appropriate Linux environment to develop on. Do the following

• Install a WSL instance (I use Ubuntu but whatever you like)
• Setup your WSL instance for C++ development
  • C++ and tools sudo apt-get install build-essential gdb
  • CMake sudo apt-get install cmake
  • nasm sudo apt install nasm
• Open CLion and create build configurations using the WSL toolchain (should auto-detect everything).