Ok, I need to dwelve into this more. Now its more confusing to be honest. If they are same or interchangeable why have 2 concept/syntax? Why not keep it simple? Was there any specific reason to have both function and closures?
Well that's the bit it gets really confusing, they are not the same, but are interchangeable, when we say "function as first class citizen", we meant "callables as first class citizen", my hypothesis is because when the term was created, most major languages at the time had no more than one type of callable down on it's AST level that was functions, but that's not the point.
In Rust all functions have a type, and all closures are a type on it's own, but both are callables.
I have no knowledge why this way, but my instinct is that maybe something related to closures ability to capture the outer environment variables and the type system and optimizations.
Ok, I need to dwelve into this more. Now its more confusing to be honest. If they are same or interchangeable why have 2 concept/syntax? Why not keep it simple? Was there any specific reason to have both function and closures?
Well that's the bit it gets really confusing, they are not the same, but are interchangeable, when we say "function as first class citizen", we meant "callables as first class citizen", my hypothesis is because when the term was created, most major languages at the time had no more than one type of callable down on it's AST level that was functions, but that's not the point.
In Rust all functions have a type, and all closures are a type on it's own, but both are callables.
I have no knowledge why this way, but my instinct is that maybe something related to closures ability to capture the outer environment variables and the type system and optimizations.
I found the blog post that are talks about this:
stevedonovan.github.io/rustificati...