RE: [Caml-list] functional or imperative feature ?

[David Allsopp <dra-news@metastack.com>]

habet_ms@yahoo.fr wrote:
> Hi,
>   are sequencing (;) and block structure (begin ... end) functional
> features
>   or imperative ones ?

Any sequence

e1; e2; e3;;

can be rewritten

let _ = e1 in
let _ = e2 in
e3;;

(with the difference that in a sequence, the compiler warns you if e1 and e2 don't have type unit) 

It's not strictly speaking an imperative construct but it's only really of use in imperative programming.

Conversely begin ... end is neither explicitly functional nor imperative - it's simply a form of brackets. Consider nested matches (definitely functional):

let f x y = 
  match x with
    `Foo ->
      begin
        match y with
          `Bar -> true
        | _ -> failwith "Bar"
      end
  | _ ->
    failwith "Foo"

HTH,


David