Hi folks, 

First post, may not follow the standards, please bear with me. 

Need to define a ufunc that takes care of various type. 

Fixed - no problem, userdef - no problem, flexible - problem. 

It appears that the standard ufunc loop does not provide means to 

deliver the size of variable size items. 

Questions and suggestions:

1) Please no laughing: I have to code for NumPy 1.3.0. 

Perhaps this issue has been resolved, then the discussion becomes moot. 

If so please direct me to the right link. 

2) A reasonable approach here would be to use callbacks and to give the user (read programmer) 

a chance to intervene at least twice: OnInit and OnFail (OnFinish may not be unreasonable as well). 

OnInit: before starting the type resolution the user is given a chance to do something (e.g. check for 

that pesky type and take control then return a flag indicating a stop) before the resolution starts

OnFail: the resolution took place and did not succeed, the user is given a chance to fix it. 

In most of the case these callbacks are NULLs. 

I could patch numpy with a generic method that does it, but it's a shame not to use the good ufunc machine. 

Thanks for tips and suggestions.

Val Kalatsky