TIL Advent of Code and Project Euler will deliberately look for puzzles where the naive solution is worse than quadratic.
This ensures that people can solve them with any programming language. You don't want fast languages to be able to use the naive solution.
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Blogging about my programming language project: choosing the basic syntax!
https://www.garden-lang.org/blog/syntax.html
Has anyone built a great solution to 'run all my unit tests automatically'?
It's straightforward to write a while loop in bash, but handling timeouts, syntax errors etc well is hard.
Running on save would be good, although I wonder if you could run fast tests on each keystroke.
TIL Tcl has a notion of 'safe interpreters', a mode where you can run untrusted code in a sandbox: https://www.tcl.tk/man/tcl8.4/TclCmd/safe.htm
Not many programming languages have this, but it's way safer to include in the implementation than try to build as a userland library.