I don't think this is a good test. Every CS graduate student has to write a lambda-calculus parser. There must be thousands of implementations on the web. It really is not strange that GPT-4 can reproduce this.
We could soon see a future where "Damn this useful paper/code is in x language. Have to wait for someone to port the code over to y language" is a thing of the past.
Interested to see how that plays out for programming languages.
A sizable portion of software devs ultimately work on something that, at its core, follows the basic CRUD pattern. The day-to-day stuff also involves a lot of boilerplate -- "public static void main" has paid a lot of mortgages over the years.
https://github.com/Aneurysm9/vm_challenge
The program will, likely, need to be amended to get the last code (last 2 codes? been a while) so you can see how it would handle updating for the new requirements.