Today I was visited by the strange sensation that I had a boss looking over my shoulder, judging how I spent my time. I have to keep reminding myself that I’m the boss now, and that the goal isn’t to maximize output/second.

(In fact, optimizing for second-to-second productivity is probably counterproductive over the long term.)

The rest of today’s post consists of notes I jotted down as I studied Rust today, especially things that surprised me coming from Python. These may seem obvious to some folks, but I didn’t even know that many of these decisions were possible when designing a programming language!

Materials used:

• The Rust Book ch. 3-4
• Rustlings exercises 00-03

Major concepts:

• Static typing
• The stack vs. the heap
• Use Box to put things in the heap
• Ownership: variables own boxes

Things that surprised me:

• We have a char type that is Unicode!
  • I think I was just excited because I want everything to be Unicode all the time
• We have to declare the type of every value in a tuple
• All values in an array have to be the same type
• Rust seems to care about single vs. double quotation marks
  • I later learned that this is for char vs. string data types
• We don’t use explicit return statements (usually)
• Rust will not convert non-Boolean types to a Boolean when evaluating conditionals (Rust doesn’t have “truthy” or “falsy” values)
  • I’m curious about why this is so! I use this in Python constantly.

Things that are cute/charming:

• “Panicking”
• Type annotations are everywhere!
• rust-analyzer automatically adds/changes annotations for the names of function parameters
• You can label loops and then use the break keyword with a label to specify which loop you’re breaking out of!

Problems that I’m having:

• rust-analyzer is extremely helpful for autocomplete, hints, etc., but it gets mad when I’m in my top “projects” directory because there’s no cargo.toml there. This is annoying because I want to keep my top directory open in VSCode and work in project subdirectories, but rust-analyzer specifically looks at which directory is “open” in VSCode.
  • I briefly reviewed some solutions online but haven’t tried any yet.
• It’s hard to visually deal with the fact that whitespace is not meaningful when looking at things like nested loops