Re: [Caml-list] exception Foo = Bar.Baz

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

On 26/07/2016 18:32, Gabriel Scherer wrote:
> I would see some use in being able to rename variant constructors, see
>
>   MPR#7102: Ability to re-export a variant definition with renamed constructors?
>   http://caml.inria.fr/mantis/view.php?id=7102

The fact that an expression "A = B" can evaluate to true can be 
confusing and really change the interpretation of constructors as atoms. 
  It's already the case for exceptions/extension constructors, but I'd 
prefer to have less of it than more.

Thinking more about it, even for exceptions, not allowing different name 
for the same constructor could be useful to optimize cases such as:


   try

     try
      ....
      raise A
      ...
     with B -> ...

   with A -> ....


If the compiler could assume that A and B were different constructors, 
it could compile the "raise" to a static jump to the handler for A, 
removing two dynamic comparisons with exception slots (and their 
associated memory accesses).


Alain