Subject: Re: [PATCH v5 02/14] trailer: process trailers from file and arguments

From: Junio C Hamano <[email-masked]>
Date: Thu, 20 Feb 2014 16:22:46 -0800

Junio C Hamano <[email-masked]> writes:

> Junio C Hamano <[email-masked]> writes:
>
> What is the right mental model the end-user needs to form when
> understanding these?  Conditions on keys go on the left, and any
> other random conditions can come as a modifier after action
> e.g. add_if_same_value_is_not_at_the_end?

Having said all that, it appears that nobody seems to be able to
come up with a saner arrangement that would not paint us into a
tough corner that we would not be able to later escape from without
being backward incompatible---I certainly didn't.

So... let's take this from your earlier message:

>> If we limit it to "if_exists" and "if_missing", the user can remember
>> that without things becoming too complex.

and go with the semantics the posted patches (I believe I have the
latest from you on 'pu') attempt to implement, at least for now.

IOW, when re-rolling, let's not try changing the arrangement to use
if-exists/if-missing (configuration variable names) for keys'
existence and include chosen set of conditions on values as
modifiers to the action (i.e. X in "do_Y_in_X").