You must have Pyret installed. See github.com/brownplt/pyret-lang.

Next:

git clone https://github.com/dbp/pyret-tc

And then build it:

raco make tc.arr

(This will take a while - on my desktop, it takes ~40 seconds. On a recent laptop, it should take maybe double that.)

Now run:

raco pyret tc-report.arr /path/to/file.arr

Which will print out a report from type checking, listing any errors detected, and any top level functions that it inferred types for based on tests.

Feedback welcome; though it is definitely still a work in progress (so, "it doesn't catch all type errors" isn't useful feedback. A specific error it missed, on the other hand, is.)

If you want to run the type checkers test suite (all the programs in the tests directory), you can run:

raco pyret tc-test.arr

Or to run a specific test:

raco pyret tc-test.arr test/functions1.arr

The tests are normal Pyret programs that have information in special comments that specify what errors and warnings, if any, the program should result in.

If you'd like to run the unit tests built into the type checker, you can run:

raco pyret tc-unit.arr

NOTE: This is a hack - tc-unit.arr is just a symlink to tc.arr, because once you raco make tc.arr, if you try to run it, it will run the compiled version, which doesn't have the unit tests. So instead we run the same file with a different name (by way of a symlink) and it all works. If you are on a platform that doesn't have symlinks, this probably won't work, and you can just removed the compiled directory and then run raco pyret tc.arr.