Mini-Project 2: Match Expressions and Error Messages

For our second mini-project, you'll be building (you guessed it) an interpreter. The mini-project is due Thursday 4/16 by 8PM. It cannot be dropped. This is the landing-page for the project, it doesn't contain the actual spec of the project.

One-Week Check-in

To verify you're making progress, you're required to submit part of the mini-project by Thursday 4/9 by 8PM. For this check-in (for 30% of the total grade) you need to complete:

the function type_of_expr for well-typed expressions whose rules are given in the Rules from Mini-Project 1 section. You don't have to worry about type errors for this check-in. This means that all our test cases will expect Ok ty as the output for some type ty. You can use assert false to fill in all other cases.
the function eval_expr for all expressions whose rules are given in the Rules from Mini-Project 1 section. You can use assert false to fill in all other cases.

This essentially means you need to complete the fragment of this mini-project that is a repeat of the first mini-project.

Good luck, happy coding