[darcs-users] [patch21] remove trailing whitespace (and 2 more)

[Ganesh Sittampalam]

Hi,

On Sat, 31 Oct 2009, Kamil Dworakowski wrote:

> A new primitive match type that allows for picking patches based on the 
> hunk contents. It takes a regex and matches the pattern inside either a 
> remove or an add line of a hunk. An example usage is:
>
> darcs changes -i --match "hunk pattern"

So, my first question is whether we really want this feature, and whether 
it fits in well with the darcs UI as it stands. My general feeling is 
it's worth having, and that it sits nicely alongside the "touch" matcher. 
By coincidence someone on IRC (sm) was just talking about doing exactly 
this kind of search. But I'd welcome further input from the watching 
masses..

> Sun Oct 25 12:29:54 GMT 2009  Kamil Dworakowski <kamil at dworakowski.name>
>  * resolve issue1636: match hunk
>
>  A new primitive match type.

My second point of discussion is about the implementation. What you've 
done makes sense to me and fits in well with the list_touched_files code. 
But both your code and list_touched_files add to the Patchy class (and
various instances) and it feels like a bit of an abstraction 
violation, and also rather boilerplatey. I have a feeling we should 
somehow generalise using some form of generic programming library before 
it gets out of hand, but I'm not experienced enough with them to pick one 
or map out what the solution would look like.

So for now I'm inclined to accept the patch as is (assuming we do want the 
feature), but we should think about how we can improve this situation.

Cheers,

Ganesh