changed \ to fn for lambda declaration

[mkhan45]

This is a really clean codebase!

A few things that would make contributing easier:

• Document how the goldentests work
• Add cargo fmt rules to a rustfmt.toml or just disable it completely (just add ignore = ["/"] to rustfmt.toml at the repo root)

[jfecher]

Changes look good :)

I agree with your points on making contributing easier, I think I'll make a Contributing wiki page so that I can expand that section with information on goldentests and possibly a FAQ in the future without cluttering the README too much.

I'll explore some cargo formatting rules too, I'm still stuck in the mindset of manually formatting things but even if I don't mind some formatting inconsistencies it does seem easier for contributors in the future to contribute with the ease of mind their formatting is acceptable.

[jfecher]

I went ahead and updated #67 too