> data Person = Person {name::String, age::Int} deriving Show

>
> Now, I can create maybe-people like in applicative style:
>
> Person <$> Just "John Doe" <*> Nothing


... field labels for building records only work
in very restricted syntactic positions, ...

To tease out that remark a little:

Data constructor `Person` is first-class; we could go

person' = Person

person' <$> Just "John Doe" <*> Nothing

But the following two are nothing like equivalent; so record syntax is not even referentially transparent:

Person{ name = "Jane Roe", age = 37 } -- builds a Person record

person'{ name = "Jane Roe", age = 37 }

In the second, the token preceding the `{ ... }` is not a data constructor (because it starts lower case), so is taken to be a variable/expression denoting a value of type `Person`; and this is datatype update syntax. Why of type `Person`? Because field labels `name` and `age` come from there, and under H98 records, they can be associated only with a single type.

Then `person'` is the wrong type, and you'll get a type error.

Although both look like a name (of function type) adjacent to a term { in braces}, neither is function application.

AntC