Re: [Caml-list] two unrelated questions

[Brian Rogoff <bpr@best.com>]

On Fri, 27 Apr 2001, Anton Moscal wrote:
> For this problem workaround exists:
> 
> let f x = 
>    let module M = struct
>         exception Break
>         let v = try ... raise Break ... with Break ->...
>        end
>    in M.v

I think the real beauty of this local module feature is that it allows
things like  a local open, which may make open more palatable to
open-phobes. For instance if you want to get a date but don't want to
"pollute" the namespace with an open'ed Unix module you can write 

let get_date () =
  let module M = struct
      open Unix
      let current_time = localtime (time())
      let current_date =
        { year   = current_time.tm_year
        ; month  = current_time.tm_mon + 1
        ; day    = current_time.tm_mday
        ; hour   = current_time.tm_hour
        ; minute = current_time.tm_min
        ; second = current_time.tm_sec
        }
    end
  in M.current_date

though I take it that these kinds of tricks weren't the original goal of
the feature. Still, the syntax is light so these are very painless
workarounds even without the P4 prettification. 

-- Brian


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