It seems to me what you need is not a coverage system but a general hook
interface.  That can be useful, bot should better be another
infrastructure than the coverage feature we have now.

Rocky Bernstein wrote:
> Sorry for not noticing sooner. It occurs to me that the built-in
> coverage feature that is currently being implemented for the next
> release is not all that different from a line tracing feature. I
> wonder if it could be extended so that a method is called instead of
> updating a hash. In fact one can think of the coverage mechanism as a
> special kind of trace mechanism that only updates a hash.
>
> And it's also true that the instruction replacement for setting a
> (temporary) breakpoint in 1.9 can also be used in implementing
> something like rcov.
>
> Here you set temporary breakpoints at every known statement boundary.
> If all you care about is coverage like rcov after the temporary
> breakpoint is serviced by updating a mark indicating the line was hit,
> the original opcode can go back and in terms of performance the only
> penalty is the initial time to put in the temporary breakpoints and
> the time to update however many counts are actually covered.
>
> And one can reliably know what has not been run by scanning the code
> for trace instructions. Finally, I suppose all of this could be sped
> up by building initial trace replacement into the compiler.
>
> On Tue, Jul 8, 2008 at 8:22 AM, Yusuke ENDOH <mame / tsg.ne.jp> wrote:
>   
>> Hi,
>>
>> 2008/7/8 Yugui (Yuki Sonoda) <yugui / yugui.jp>:
>>     
>>> Committers and anyone who intend to write patches, let me know your
>>> plan. What features will be implemented by 25 Sep? What will not?
>>>       
>> I hope to include built-in coverage measurement feature.
>>
>> I have already committed some primitive features that measure
>> coverage into the core interpreter.  But I haven't implemented
>> a practical front-end tool which controls measurement and outputs
>> the measured result.
>>
>> As a matter of fact, my goal is to measure coverage of the
>> standard libraries for maintenance and enhancement of their tests,
>> not to provide useful coverage measurement tool.  So I'm not in a
>> hurry to implement a front-end tool.  If it's permitted, let's
>> just say that it will be implemented by 1.9.5 :-)
>>
>> --
>> Yusuke ENDOH <mame / tsg.ne.jp>
>>
>>
>>     
>
>
>
>