[Twisted-Python] Goin' with the Flow

[Clark C. Evans]

Nicola,

Thank you for taking time to play with flow.  I'm working on an LDAP adapter 
and shortly there after will somehow find a way to get async PostgreSQL 
queries to work with it (instead of using the Threaded/QueryIterator hack).
However, recently I've been caught up with an unexpected move and have 
been job hunting, which has limited my time for Twisted (and YAML).  But,
that should straighten out in the next month or so... and then I'll be
back at it.

Flow will be more easily understood with an application that uses 
it... I've been putting together a simple LDAP browser (using OpenLDAP)
and ldap queries using Twisted/Flow and python-ldap.   It also will
use iCal and PostgreSQL queries.   The current app I have which uses
Flow is proprietary (*sigh*) so I can't post it.   In short, flow is
useful when:

   1.  You have a ton of deferred calls and would like to keep
       the logic as a single "function".   Or, in other words,
       you are implementing a state machine which can allow other
       twisted requests to be handled during each state change.

   2.  You need to have results returned incrementally, and deferreds
       arn't quite working for you in this regard.

Best,

Clark