Cubical formalization of Basic Categorical Type Theory
Trying out cubical agda formalizations of different approaches to categorical semantics of type theories.
Cubical Version
This development heavily relies on some extensions to the cubical agda stdlib that covers representability of presheaves which are under `Cubical/`. I expect these to be merged upstream eventually.
Style and Build Tests, Or : How to Get a Green Checkmark
To fit with the Cubical style, we have a check that the displayed text in each Agda file fits within 80 characters width. This is complicated by the use of unicode characters, so in .github/workflows/main.yml we run a python script that calculates the width of each line accounting for the variable size of unicode characters. If you’re currently reading this sentence it means, I have not written anything to do this locally (until then please be good and keep things withing 80 characters).
There are also style constraints on whitespace that are used upstream, so we check those with the fix-whitespace whitespace utility. This checks things like trailing whitespace, tabs v. spaces, etc. To run the check for this, execute fix-whitespace --check. If you remove the check flag it will automatically fix any issues it finds.
To check if all of the repository compiles, run make test. If you want a list of which files do not compiles, run make test-and-report. Note that make test is what is ran on each push, so it also does the above whitespace checks.