LLVM IR rejects 1.3 as a floating-point constant, since it can't be represented exactly in binary. Smart way to avoid confusion.
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Bril is a cute intermediate language for teaching (think simplified LLVM IR): https://www.cs.cornell.edu/~asampson/blog/bril.html
The idea of providing a standard JSON format to help students write basic passes is really elegant.
The most common selling point I hear for Nix is having a list of all the packages you need.
On a traditional Linux distro, I just install things and forget about them. A curated, commented list would certainly be handy when I have a new system.
It's rare to see ANSI escape codes for URLs in the wild, but cargo has it!
This example links to https://doc.rust-lang.org/cargo/reference/profiles.html#default-profiles, describing the different profiles.
Considering releases vs debug is a source of confusion for new users expecting better performance, this seems wise.