You mean like a REPL? Most languages are unusable for interactive programming. And it's not a downside if it stops use in a domain that was nobody's goal.
Yes, just pointing out the trade offs here. Btw many functional languages have quite good interactive experiences, (ocaml, f sharp, Haskell , clojure all have decent repl's). Usually they work instantly for small sized projects.
Have you ever seen a procedural language with a good REPL? Python maybe, but definitely no compiled procedural garbage-collectorless language. The "needing to put type signatures" is completely unrelated. I have no idea how that would stop Rust from being good in a REPL.
Can’t speak to its quality, but there’s nothing stopping someone from writing a repl from a sufficient compiler API... and “good” is only limited by inference quality and runtime performance. IDEs are pretty snappy at showing you autocomplete as you type regardless of whether the language has a garbage collector. And performance - well, that’s what caching would be for, and an optimized compiler design that only needs to recompile changed code...
I would also point out the “auto” keyword in CPP likely saves folks a lot of typing ;-) I know it and similar inferences changed my mind on the whole static vs dynamic debate...
