[e-lang] Non-local Exits vs Defensive Consistency - David Wagner

[Mark Miller]

---------- Forwarded message ----------
From: David Wagner
Date: Jan 28, 2007 8:13 PM
Subject: Re: Defensive consistency and exceptions

> The special issue with VirtualMachineErrors versus other exceptions is
> that the possibility of such Errors makes it impossible to write code
> that is guaranteed not to throw. For example, I can't write a private
> helper function that is trusted by the containing object to do some task
> without causing an exception. Just calling the helper function will
> allocate another stack frame, which may be one too many, resulting in a
> java.lang.StackOverflowError. VirtualMachineErrors make it too hard to
> implement the object's own internal logic.

Good point.  I missed that issue.  Thanks for an enlightening discussion!

> The programmer will instead use an eventual sending API.

Yup, that'd take care of the issues with exceptions thrown by method calls
that cross a trust boundary.  Thanks.