line number from exceptions

[Allison Randal]

Robin Edwards wrote:
> Hi,
> 
> I am trying to throw an error on a type mismatch through an assignment operator.
> 
>     ex = new 'Exception'
>     ex['severity'] = .EXCEPT_ERROR
>     ex['message'] = "Type mismatch in assignment!"
> 
> I can't find a away of leaving the user with a code line number is
> this possible?
> 
> I have tried trying to grab '$/' to with no success any ideas?

Hi Robin,

Hmmm... Your code sample above is PIR, but $/ is Perl 6 syntax (for 
output record separator, last I checked). It might be helpful to know 
what you're working on.

In PIR/PASM, Parrot captures the line number and displays it in the 
output of an uncaught exception. Run the following PIR subroutine as an 
example:

.sub main :main
     .include 'except_types.pasm'
     .local pmc ex
     ex = new 'Exception'
     ex['severity'] = .EXCEPTION_SYNTAX_ERROR
     ex['message'] = "Type mismatch in assignment!"
     throw ex
.end

If you're working on a language implementation, you may want to use the 
.annotate directive to set the line number for the original language source.

Allison