I see, where I was wrong. But if the goal is to avoid allocation then
something like

[ Rtag (x, y, z, w)] -> somefn x y z w

will work

On Thu, Oct 19, 2017, 17:35 Gabriel Scherer <gabriel.scherer@gmail.com>
wrote:

> This is a small hiccup with the OCaml (non-revised) syntax:
>
>   | Foo of bar * baz * blah
>
> and
>
>   | Foo of (bar * baz * blah)
>
> are not equivalent, and only the latter allows to do what you want.
>
>
> On Thu, Oct 19, 2017 at 3:38 PM, Matej Košík <mail@matej-kosik.net> wrote:
> > Hi,
> >
> > I am trying to do simple pattern matching of these values:
> > https://github.com/ocaml/ocaml/blob/trunk/parsing/parsetree.mli#L145
> >
> > What I would like to do is:
> >
> >    | [Rtag the_whole_4_tuple] ->
> >        the_whole_4_tuple
> >
> > However, when I try to do that, I am getting:
> >
> >   Error: The constructor Rtag expects 4 argument(s),
> >          but is applied here to 1 argument(s)
> >
> > This:
> >
> >     | [Rtag (f1,f2,f3,f4)] ->
> >         f1,f2,f3,f4
> >
> > of course works but (regardless of the chosen bound variable names), it
> looks amateurish.
> >
> > What's the right way to do this?
> > (I would like just to bind a 4-tuple and then return it)
> >
> > (Apologies in advance for a stupid question.)
> >
>
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