Taylor Campbell wrote:
> Scott and I seem to disagree on this.  Here's a log of our debate about it
> on IRC tonight:  (I'm Riastradh; Scott is FoxFire)
>
> <Riastradh> Dictionaries' *-GET should take an optional failure
> continuation, not default value.
> ...

I would very much like to see *any* kind of function (promise,
continuation, procedure) there rather than simply a default value.

The use of exceptions is a popular style.  Also there are more exotic
applications such as using a secondary retrieval on a cache failure.

I believe a procedure taking the arguments supplied to the original call
(whether fold, get, update), although a bit ugly, would easily support
any application need without a performance penalty when simply providing
a fixed default value.

Jim
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