Closure vs closure expression

[hollance]

I read this the other day: http://airspeedvelocity.net/2014/06/16/closures-and-closure-expressions-are-two-different-things/

I think it's good to use proper terminology in our style guide. A closure is something that captures from its environment. This can be a named function or it can be an anonymous inline function, aka a closure expression, defined with just { }.

In other words, just because you use { } to define a block of code doesn't necessarily make it a closure.

[gregheo]

Well I'm glad the linked article recognizes itself as "pedantry" ;]

From the Swift Programming Language book:

• "Global functions are closures that have a name and do not capture any values." – so "closures" don't necessarily have to capture anything.
• "Closure expressions are unnamed closures written in a lightweight syntax" – so "closure expressions" are "closures" too.

The way I see it, saying "closure" pretty much includes everything we're talking about. That doesn't mean it's correct in a pure CS classroom, but that's how Apple is using it.

That said – where in the style guide do you think we should say "closure expression" instead of just "closure" ?

[gregheo]

Bump? If there are any places where we should say "closure" vs "closure expressions" (or vice versa) – pull request!