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Proposal for exception handling
| Date: Fri, 15 Sep 1995 03:41-0400
| From: email@example.com
| Scheme should definitely provide a way to define new opaque types.
I disagree strongly. See below.
| Since I *have* been through it more than once now and since I *do* have an
| idea of what I want, here's a list of what I'd like to see in a condition
| system. This is very rough and is not a formal proposal. It also omits
| most of the useful syntax I'd want to add (other than ignore-errors) and
| focuses on primitive functionality. I don't have time to spend doing a
| full proposal, but I hope someone will at least ponder whether someone
| else should find the time. I'd be happy to review any such proposal.
| (make-condition kind ...data...)
| Some mechanism for making an object of an opaque type that is possible
| to (a) recognize as a condition, (b) inspect data within, and (c)
| perform other services common to all conditions.
This is not an opaque type! It can be inspected! It is a _unique_
new type (distinguishable from all others), but not opaque.
I'm very much in favor of the creation of new unique types, but I
don't believe in opaque types at all. They prevent me from writing
pretty-printers, debuggers, general parsers, etc.