does (spec.test/instrument) (w/o args) instrument 1. all functions (ie vars) in all namespaces, mine, libs, and clojure? or 2. just the current one? thanks!

This might be answered, but I watched Matthias Felleisen's talk about types: "Types are like the Weather, Type Systems are like Weathermen". And I remembered clojure.spec and noticed that it somehow reflects his ideas (putting contracts instead of making a type system for an untyped language, e.g. typed.clojure [which afaik is now discouraged/discontinued] and that type inference is near to impossible to implement in a untyped language like Clojure). So the question is ... is clojure.spec the answer to Felleisen's talk?

no, although spec was influenced by Racket's contracts, along with other stuff

spec had been in development for about 4 months at the time of that talk

"typed.clojure [which afaik is now discouraged/discontinued]" -- I thought Ambrose was still actively working on this...?

he just defended his dissertation on it

so it has been, but not sure where it's going from here. would be a good question for him

iirc, while I was away at Clojure/west when that talk was given, Rich wrote all the regex stuff in spec

thanks @alexmiller, although it didn't came directly from racket's contracts, I'm still glad that they're going almost on the same direction (no type inference, or implementing a type system [just to say we also can do type checking]).

well, it's not type checking, and the difference is important

type checking is about proving things early

spec is about verifying predicative constraints dynamically