Version française
Home     About     Download     Resources     Contact us    
Browse thread
Revised syntax scope (3.10 vs. 3.11)
[ Home ] [ Index: by date | by threads ]
[ Search: ]

[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: -- (:)
From: Nicolas Pouillard <nicolas.pouillard@g...>
Subject: Re: [Caml-list] Revised syntax scope (3.10 vs. 3.11)
Excerpts from Andre Nathan's message of Fri Mar 27 05:42:34 +0100 2009:
> Hello
> 
> I've found the following difference of behavior between OCaml 3.10 and
> 3.11. The code below
> 
>   <:expr<
>     do {
>       let a = "foo" in
>       print_endline a;
>       print_endline a
>     }
>   >>
> 
> when run through camlp4o becomes, in 3.10,
> 
>   let a = "foo" in (print_endline a; print_endline a)
> 
> while in 3.11 it becomes
> 
>   ((let a = "foo" in print_endline a); print_endline a)
> 
> which causes `a' to become out of scope in the second print_endline.
> Is the behavior of 3.11 the correct one? I had to move the binding
> of `a' out of the do block so that this works in both versions.

That was indeed the intended behavior, to get a larger scope for 'a'
use this syntax:

  <:expr<
    do {
      let a = "foo"; (* <--- semicolon here *)
      print_endline a;
      print_endline a
    }
  >>

-- 
Nicolas Pouillard