Calc is a proof of concept to implement a simple arithmetic language interpreter with JIT compilation, using either LLVM or a more low-level JIT based on GNU Lightning.

A fun weekend project, if you ask me!

You need LLVM and GNU Lightning installed. On Mac OSX:

$ brew install llvm

Unfortunately the version of Lightning in Homebrew is broken. Download and install lightning from its mirror git repository.

Now:

$ git clone git://github.com/txus/calc.git calc
$ cd calc
$ make

You get the calc executable.

Using the AST-walking interpreter:

$ ./calc "3 * (4 + 5)"

Using the LLVM JIT compiler:

$ ./calc --llvm "3 * (4 + 5)"

Using the lower-level, GNU-lightning based JIT compiler:

$ ./calc --jit "3 * (4 + 5)"

It's just integers, these operators: + - * /, and parentheses for precedence.

This was made by Josep M. Bach (Txus) under the MIT license. I'm @txustice on twitter (where you should probably follow me!).