[erlang-questions] Avoiding case nesting

[mayamatakeshi]

On Mon, Sep 28, 2009 at 7:38 PM, Gleb Peregud <gleber.p@REDACTED> wrote:

> On Mon, Sep 28, 2009 at 12:23, mayamatakeshi <mayamatakeshi@REDACTED>
> wrote:
> > So, is there a way to avoid this cascading of case expressions?
>
> One could do this:
>
>     Prefixes = [{"prefix1", fun do_this/1},
>                 {"prefix2", fun do_that/1},
>                 {"prefix3", fun do_something/1}],
>     catch lists:foldl(fun({Prefix, Fun}, Tail) ->
>                   case checkprefix(Prefix, Tail) of
>                       {ok, NewTail} ->
>                           NewTail;
>                       _ ->
>                           throw(done)
>                   end
>               end, String, Prefixes).
>

This works.
I'm a little concerned about the run time cost of throwing exceptions to
force early processing termination (this will be called a lot) and this
really seems somewhat abusing, but I will not discard this without checking
performance.
Thanks.