lang

lang is a simple stack based programming language written in Python. It can either be interpreted in Python, or be compiled to x86_64 assembly code using nasm. Note that the compiled executables will only run on 64 bit linux distributions since linux syscalls are used, although the Python simulation mode should work on all modern operating systems.

Installation

1. Clone repository
2. Make sure you have nasm and ld in your path as these are used for compiling programs
3. Install python dependcies:
   • pip install pathlib
4. Try to run one of the example files:
   • Try to simulate: ./main.py examples/fib/fib.lang simulate and
     
   • Try to compile: ./main.py examples/dib/fib.lang compile examples/fib/fib.asm
   • Try to run the compiled file: ./examples/fib/fib
5. Add the main.py to your system path somehow, e.g. save a bash script called lang in your ~/bin:

   ~/coding/lang/main.py "$@"

   Then, you can do lang [program] [simulate | compile <out-file>]

Usage

Write a program with .lang extension, for example program.lang. Then you can either simulate it in Python with lang program.lang simulate. You can compile it to x86_64 assembly with lang program.lang compile program.asm. The compiled assembly code will be stored in the file specified, in this case program.asm. Additionally, an object file program.o will be generated, and the actual executable, simply named program with no extension. To run it, run ./program.

Features

lang (name not final) is a very simple stack based language, and currently does not have features you might be used to like variables, etc. Instead, you work with a stack. A program consists of a series of instructions. Instructions are separated by spaces, and newlines and excess whitespace are ignored. You can use # to type comments, anything afer a # will be ignored.

Currently the only type of data that is supported is signed integers. Nested if-else blocks and loops are supported.

Examples

Code examples can be found in the examples directory, but here is an example program that calculates the fibonacci numbers less than or equal to 1000 and prints them to standard output:

1 1 while
  dup dump
  swap dup2 +
  dup 1000 >= if 0 end
end