Re: [Caml-list] Changing precedence and placement of attributes

[Alain Frisch <alain.frisch@lexifi.com>]

On 03/09/2015 02:16 PM, Maxence Guesdon wrote:
> I'm quite "shocked" as it becomes inconsistent with other precedences
> in type definitions. By now
>    int * int list
> is parsed as
>    int * (int list)
> and not as
>    (int * int) list
>
> I would expect attributes to be associated the same way.

Attributes really don't behave as type constructors; for instance,

    (int, int) [@foo]

is not allowed in type expressions.


I'd be more concerned about how attributes behave across various 
syntactic categories for similarly looking fragments.  For instance, in 
expressions

   x * y [@foo]

is already currently parsed as

   (x * y) [@foo]


But
  - "x, y [@foo]" is parsed as "x, (y [@foo])"
  - "x * y [@foo] * z" is accepted as an expression, and parsed as "(x * 
y)[@foo] * z".

> How would be parsed the following:
>    int * int [@foo] * int
> ?

This would be rejected.  Doing the same as for expression would be 
weird, since * is a n-ary construction in types, not a binary operator.

(Note: Jérémie prepared a nice table in his pull request 152 on Github; 
it shows how various forms are interpreted currently and after the change.)


Alain