Re: [Caml-list] Row-polymorphic type declarations

[Jacques Garrigue <garrigue@math.nagoya-u.ac.jp>]

Others answered your questions, but they have missed what I think is probably just a typo:

On 2014/06/10 03:50, Jordan W wrote:

> 4. It appears there are two ways to write the row-polymorphic type annotation:
> type 'a t = ([> `Red ] as 'a) and type 'a t constraint 'a = [> `Red ]. Why are there two ways and what are the advantages?


type 'a t = ([> `Red ] as 'a) and type 'a t = 'a constraint 'a = [> `Red ] are equivalent,
where the parameter is just a trick to allow a row variable inside a definition,
but type 'a t constraint 'a = [> `Red ] is an abstract type, whose parameter is constrained,
so it is different from any other type.

	Jacques