While the discussion about how to refactor test framework is not
finished (#1654), make this change: move `rm -rf build` in the
beginning of the test. For these reasons:
* it is useful to inspect the contents of the `build` directory
especially after the test failure
* if build crashes mid-test (e.g. process killed), next run should
not be affected by the `build` directory from the previous run
This saves a small amount of allocation, especially since we never
actually look at the tag in a record. We can use null? for Nothing just
like for Nil.
- Added initial implementations for terms and values
- Error messages converted to pretty printer
- Colorization for error messages
- Color and console width option both as command line and repl command
This is added to functions which are guaranteed to be productive. The
check is currently very conservative - just added when every clause is
constructor headed (or headed by an AllGuarded function), and there are
no other function applications.
