Because you can read proportional fonts faster than monospaced fonts. The difference in character widths allows you to see words by their shapes more readily.
Yes, it’s an old thread, but the discussion is an important one. I’m dismayed to see a language with such promise implementing a language-level standard on something so indelibly subjective as whitespace. I come from a C++ background, and one of its perks is that it doesn’t waste time on establishing such drivel. The term “bikeshedding” was employed above, and I can’t fathom more fitting circumstances for its use.
It’s my project. It’s my code. I will set the coding style as I deem appropriate. End of story.
Alright, alright, now everybody please hold on just a moment here!
The document that this topic has largely been about is a bit old, and—as people have brought up, it is not entirely about API guidelines… but there is a new document in the works, which the rust-libs team has been building with wisdom gained through the Rust Libz Blitz: