[r6rs-discuss] "Unspecified"
AndrevanTonder
andre at het.brown.edu
Fri Sep 22 13:57:57 EDT 2006
On Fri, 22 Sep 2006, William D Clinger wrote:
> This problem could
> have been solved by requiring continuations that
> expect a single value to coerce zero values into
> an unspecified value, or into some specific value
> (e.g. the oxymoronic unspecified value), but the
> editors decided not to require that.
I don't quite understand why one would want this coercion
to happen. It would seem to be more useful if an error
occurred - I refer to my problem of discovering #<unspecified>
values of obscure origin in a data structure and then having
the difficult task of figuring out which call in the history
of the computation could have caused them.
This is much less of a problem in a typed language like ML, but
in Scheme there is value in discovering these "type errors"
sooner rather than later.
Andre
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