From: Jonathan Scott Duff <[EMAIL PROTECTED]>
Date: Sat, 30 Sep 2006 17:23:54 -0500
On Sat, Sep 30, 2006 at 11:48:04AM -0700, Joshua Choi wrote:
> How does automatic coercion work?
[ deletia ]
> 1. C<sum()> automatically coerces its C<Str> arguments into C<Num>
> parameters because C<Str.does: Num>.
Wouldn't it be better to do the coercion explicitly? E.g.:
multi sum ( Str $addend1, Num $addend2 --> Num ) { sum 0+$addend1, $addend2 }
multi sum ( Num $addend1, Str $addend2 --> Num ) { sum $addend1, 0+$addend2 }
After all, there may be more than one way to do the coercion, especially
for something more complicated than a number.
> 2. C<say()> then automatically coerces its C<Num> arguments into
> C<Str> parameters because C<Num.does: Str>.
>
> ...Or am I completely off the mark?)
I hope you're way off the mark. Automatic coercion was one of the
annoyances I remember from C++. Debugging becomes more difficult when
you have to not only chase down things that are a Foo, but anything
you've compiled that might know how to turn itself into a Foo.
I tend to agree, FWIW.
-- Bob Rogers
http://rgrjr.dyndns.org/
