Re: [RFC] or ACLs

From: Alex Rousskov <rousskov_at_measurement-factory.com>
Date: Wed, 26 Sep 2012 09:07:54 -0600

On 09/25/2012 09:02 PM, Amos Jeffries wrote:

>> So, if we change the name to "any/one-of/first-of/etc" or use the "is/="
>> syntax above, will you be OK with adding OR ACLs?

> Does 'is' mean OR or AND or IF or equals ?

"is" means what it means in English: equality or definition.

> Does '=' means OR or AND or assignment ?

"=" means what it means in programming: equality or assignment.

The expression on the right hand side determines what is being assigned.
Since neither of us liked "or acl1 acl2" style, I proposed "is acl1 or
acl2" style because it is natural and will allow us to support more
complex expressions later. I now understand that you do not like that
direction, so I will use "one-of" you suggested unless others help form
a different consensus.

> Please consider names that provide you with easily distinguishable set
> of types that still match the underlying semantics. "one-of"/"all-of" at
> least hint at the OR/AND set semantics.

I will use your "one-of"/"all-of" names.

> To summarise: Yes I'm okay with adding OR type. Provided the larger
> picture is considered when adding them.
>
> You may as well add the AND type as well, since they only differ in
> match() strategy. Then you have grounds for adding a Conditional.h/cc to
> src/acl which defines these and any future boolean node types.

I am glad AND/OR ACLs will be allowed.

It is unfortunate that our views on what the ideal Squid configuration
language should provide (and how to get to that ideal) differ so much. I
focus on maximizing flexibility and expressiveness of the language while
you focus on minimizing misuse and abuse. I cannot think of any
real-world example where humanity succeeded optimizing in _both_
directions. While both expressiveness and safety are good principles and
usually co-exist, one principle has to dominate for the design to flourish.

Now that the solution to an immediate practical problem has been agreed
on, I do not think it makes sense to continue this discussion between
the two of us. Hopefully, others will chime in and help form a
consensus, but I am not optimistic.

Thank you,

Alex.
Received on Wed Sep 26 2012 - 15:08:02 MDT

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