official python interface for mercurial

[Chad Dombrova]

On May 18, 2010, at 4:52 PM, Benoit Boissinot wrote:

> On Tue, May 18, 2010 at 7:49 PM, Chad Dombrova <chadrik at gmail.com>  
> wrote:
>> this is something that i am also very interested in.
> The following is orthogonal to the original request.

my interest in an official API is not for the sake of stability as was  
the case with the original request.  what i hoped to gain from an  
"official python interface" is an API with more features targeting  
developers wishing to integrate mercurial into python applications.   
my problem with the internal API is that it is, quite understandably,  
designed with internal use in mind.    IMHO, a good API would take  
more than refactoring existing code, although that would help, it  
would also constitute utilities not internally used by mercurial, but  
which every third party developer building tools with mercurial has to  
rewrite since no official library seems to exist.  tortoisehg.hglib  
might be a good starting place.

this thread coincided with another on the tortoisehg list about  
creating a better dispatch runner:  http://groups.google.com/group/thg-dev/browse_thread/thread/31840c1401844873?hl=en

the need for this sort of utility stems from the fact that the  
mercurial api is targeted at creating a command-line program where  
each action is atomic: startup, do something, quit. as a result, there  
is currently no clean and easy way that i know of to do the following  
with the context of a python program:

	bootstrap mercurial, loading all extensions
	call a mercurial command, triggering pre- and post- hooks
	call another mercurial command, triggering pre- and post- hooks

by clean i mean, not using syntax like this:

	_dispatch('update', '-C', '-r', '100'])

....and instead using syntax like this:

	commandrunner('update', clean=True, rev=100)

in the coming weeks i plan to take a stab at refactoring  
mercurial.dispatch to be more "external app friendly".  basically, i  
hope to break it apart so that we can get entry somewhere between  
_dispatch and runcommand.  we'll see how it goes.

for all of those features that can't be achieved through refactoring,  
it would be great to see an officially blessed hgutil module.

-chad