* Ovid <[email protected]> [2010-04-07 09:05]:
> Presumably the format should try to determine the number of
> conversions in the format and perhaps the alias could generate
> a sub with a corresponding prototype like 'sub
> throw_io_read($$)'. That might give you a touch of compile-time
> safety. Haven't really thought too carefully about this,
> though.
I think the best approach would be to tie String::Formatter into
Exception::Class, specifically its `require_named_input` and
`named_replace` options. To produce its message, an exception
class would pass its declared fields as format inputs. Then
resulting interface would look like this:
use Exception::Class (
'MyException',
'IOOpenRead' => {
isa => 'MyException',
alias => 'throw_io_open',
fields => [ qw( file mode errno ) ],
format => 'Cannot open %{file} for %{mode}ing: %{errno}',
},
);
You’d use that like so:
open my $fh, '<', $filename
or throw_io_open file => $filename, mode => 'read', errno => $!;
Regards,
--
Aristotle Pagaltzis // <http://plasmasturm.org/>
