Promoting to Complex

[Patrick R. Michaud]

On Sun, Sep 26, 2010 at 01:58:13PM -0400, Paul C. Anagnostopoulos wrote:
> Folks,
> 
> Should PMC functions with partial complex ranges promote their result to a
> Complex? For example, should sqrt(negative Float) produce a Complex? 
> This issue does not pertain to native numbers, since we never promote 
> them to PMCs.

I would tend to vote "no" here.  Most languages would expect
sqrt(negative Float) to throw an exception, and if a language
wants the possibility of a complex result it's trivially simple
to promote a Float to a Complex prior to calling the function.

Pm