jckarter/clay — pull request #356 by stepancheg (2012-08-20 18:30:12+00:00)
Title: core.exceptions: customizable unhandled exception callback

Given code:

```
record MyExc (a: Int);

instance Exception (MyExc);

main() {
throw MyExc(12);
}
```

Default version (when `printer.exceptions` module is not imported) prints:

```
unhandled MyExc exception
```

Extended version prints:

```
unhandled exception: MyExc(12)
```

`printer` module imports `printer.exceptions`.