[erlisp-devel] Re: receiving, pattern-matching

[Gerd Flaig]

Faré <fahree at gmail.com> writes:

> What should happen when you receive something that doesn't match any
> pattern? I don't remember what happens in Erlang: either the message
> is dropped or it raises an error, I suppose (gotta read the
> documentation). In Lisp, it could be configurable. See match vs ematch
> just like we have case vs ecase.

unmatched messages are buffered. I've attached a small test module
demonstrating this.

     Goodbyte, Gerd.

-module(f).
-export([r/0]).

l() ->
    receive
    {a,A} ->
        io:format('a: ~p~n', [A])
    end,
    receive
    {b,B} ->
        io:format('b: ~p~n', [B])
    end,
    receive
    R ->
        io:format('r: ~p~n', [R])
    end,
    l().

r() ->
    Pid = spawn(fun l/0),
    Pid ! {b, bla},
    Pid ! foo,
    Pid ! {a, blubb}.

Eshell V5.4.6  (abort with ^G)
1> c("/tmp/f", [{outdir, "/tmp/"}]).
{ok,f}
2> f:r().
a: blubb
{a,blubb}b: bla

r: foo
3> 

-- 
The last thing one knows in constructing a work is what to put first.
                -- Blaise Pascal