[r6rs-discuss] [Formal] FIND delivers an ambiguous value

[Eli Barzilay]

On Nov  1, AndrevanTonder wrote:
> On Wed, 1 Nov 2006, Shiro Kawai wrote:
> 
> > But still, it's so frequent that it would deserve an abstraction.
> 
> You and Eli have convinced at least me, with the following caveat:  I am 
> wondering if anyone would object to
> 
>   - keeping "find" as is, but
>   - raising an error if the returned element would have been #f.

(Actually, I thought about a similar solution: raise an error if the
input list has #f, but that'll disqualify some useful cases.  Your
suggestion is better.)


> This seems to attain the best of both worlds by keeping the
> convenience and avoiding the inaccuracy and fragility.

It'll be even better if it raises an error if #f would have been
returned -- and no default value was specified.

-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!