LoxLox

LoxLox is an interpreter for Crafting Interpreters' Lox language written in ... Lox.

Below are a few notes about running LoxLox, but you can read more about LoxLox here.

How to run LoxLox

First clone the LoxLox repo as well as the Crafting Interpreters one:

$ git clone https://github.com/benhoyt/loxlox
$ git clone https://github.com/munificent/craftinginterpreters

JLox

Then patch the Crafting Interpreters repo to add the required builtins to JLox (getc, chr, etc) and build JLox:

$ cd craftinginterpreters
$ git apply ../loxlox/jlox_diff.patch
$ make jlox
$ cd ../loxlox

Now you're ready to run LoxLox (input is passed to LoxLox on stdin):

$ 
$ ./jlox lox.lox < example.lox
1
4
9
16
Waddles quacks
6
105
$ ./jlox lox.lox < sum.lox 
4.99995E9
$ echo 'print "Hello world!";' | ./jlox lox.lox 
Hello world!

CLox

Thanks to gloria-mundi's patch, you can now even run LoxLox under CLox. Patch the Crafting Interpreters repo in much the same way as above:

$ cd ../craftinginterpreters
$ git apply ../loxlox/clox_diff.patch
$ make clox
$ cd ../loxlox

You should now be able to run the examples the same way as above, but replace ./jlox with ./clox. It's about 6x as fast -- see the benchmarks!

Running the tests

To run the Lox test suite under LoxLox, use this command:

$ python3 test.py

Note that several tests will fail. That's expected -- the code works; the remaining failures are only from differences in the runtime error messages between JLox and LoxLox.

To run the tests and diff against the git-committed failures file (should be no diffs):

$ python3 test.py > failures
$ git diff failures

Contact me

Contact me if you have any feedback or suggestions. And if you get LoxLox to run under LoxLox ... mind blown.