multiple patterns per clause?

[Richard Carlsson]

Yariv Sadan wrote:
> Is it possible to have a single clause match multiple patterns in Erlang?

Short answer: no.

> Specifically, I want to test if a list has a number of different
> prefixes, all of which would lead to the same expression.
> [...]
> I know the above is illegal, so what's the easiest way of doing
> something similar in Erlang?

   case L of
     [$f|_] -> handle(L);
     [$x|_] -> handle(L);
     [$a, $b, $c | _] -> handle(L);
     _ ->
       ...
   end.

   handle(L) -> ...

The calls will basically be goto:s. It's not terribly verbose,
and in some cases it can even makes the code more readable.

A tip: if you have many variables to pass on, try this:

   H = fun () -> handle(L, X, Y, Z, P, Q, R, S, T) end,
   case L of
     [$f|_] -> H();
     [$x|_] -> H();
     [$a, $b, $c | _] -> H();
     _ ->
       ...
   end.

	/Richard