allow multiple catch blocks

[StefanKarpinski]

One ought to be able to write something like this:

try f()
catch e::NoMethodError
  # handle no method error
catch e::SomeOtherError
  # handle some other error
catch e
  # handle any thrown object
end

Although it needn't actually be implemented by creating a generic function, this should probably emulate the behavior of dispatch, implying that clause order doesn't matter.

[JeffBezanson]

I assume the semantics are that if none of the catch clauses match, the handler is skipped and we go to the next one down the stack?

[StefanKarpinski]

Yes, exactly.

[ViralBShah]

I like this and it fits the multiple dispatch style of programming nicely.

[JeffBezanson]

Can now be done with if and rethrow. We also decided that catching exceptions by type does not really make sense. You either catch all exceptions (and possibly rethrow), or unwind to a specific handler by label (to be implemented later).