Re: [PATCΗ] Quoted values in squid.conf

On Sun, May 26, 2013 at 7:29 AM, Alex Rousskov
<rousskov_at_measurement-factory.com> wrote:
> On 05/25/2013 09:30 PM, Amos Jeffries wrote:
>> On 24/05/2013 7:38 a.m., Tsantilas Christos wrote:
>>> This patch :
>>>
>>> - adds support for quoted values in the entire squid.conf
>>>
>>> - warn about or prohibit values that can no longer be interpreted as
>>> either quoted strings or simple tokens
>>>
>>> - support file:"path/to/file.name" syntax to load external configuration
>>> files
>>>
>>> - support macros in "double quoted" values
>>>
>>> - support 'single quoted' values that do not expand macros
>
>
>> Firstly, Design simplicity:
>>
>> I do not believe we need to present such a wide range of potential
>> quoting and escaping mechanisms for squid.conf. We need to pick one
>> style which will be familiar to our administrators and ignore the other
>> styles. Double-quoting with \-escaping of " characters for strings is
>> very well known and the type of encoding most often requested.
>
> I do not want to step on Christos' toes, but since I asked him to add
> support for 'single quoted' strings, I feel obligated to respond to this
> part of the review.
>
> While I agree that reducing the number of mechanisms is an important
> optimization vector, the remaining mechanisms should be expressive
> enough to form a convenient configuration language. IMO, preventing all
> macro expansion in strings using single quotes is useful and common
> enough (e.g., shell and Perl) to be supported along with double quoted
> strings. I recommend but do not insist on its inclusion (until we have
> enough user demand to back me up).
>
> Other opinions?
>> IMO, we should drop the '-quoted string handling from this. It is the
>> first step on a slipery-slope toward arbitrary quoting styles and "why
>> not also add {-quoted strings or [-quoted strings?". Those are becoming
>> equally popular as people become familiar with YAML/SAS/JSON syntax.
>
> Single quoted strings were added not because they were popular but
> because they offer a unique functionality -- string-global suppression
> of macro expansion. If {-quoted string or [-quoted strings offer
> something equality useful they should be _considered_.

Single- and double- quotes have a well-specified meaning in shell
scripting and some other languages (e.g. PERL). From your description,
it seems that this behavior is implemented, so I believe there is
benefit and no confusion from having both.

The only thing I would like to see differently implemented is the
syntax used to include files:
file(path) would be IMO easier to understand and less prone to
confusion than the proposed syntax.

--
    /kinkie