Re: [gentoo-dev] RFC: Future EAPI version operator changes

[konsolebox]

On Tue, Nov 8, 2016 at 3:09 PM, konsolebox <konsolebox@×××××.com> wrote:
> On Sun, Nov 6, 2016 at 6:52 PM, Michał Górny <mgorny@g.o> wrote:
>> Hi, everyone.
>>
>> Following my previous RFC wrt version operator problems, I'd like to
>> start the second part of the discussion: how to improve version
>> operators in a Future EAPI?
>>
>> I've collected various ideas on operator changes on a wiki page [1].
>> I've tried to stay open-minded and cover every possibility, even though
>> I doubt some of them would be even considered.
>>
>> I should warn you that some of the solutions are interlinked to each
>> other, and you probably need to look through the whole page first
>> before starting to construct an opinion. For example, specific
>> solutions to most of the problems depend on whether we enable version
>> ranges and in which form.
>>
>> I think we should start by loosely discussing the various ideas
>> on the wiki page. Feel free to also point out any missing ideas
>> or remarks that would be useful there.
>>
>> So, what are your comments?
>>
>> [1]:https://wiki.gentoo.org/wiki/Future_EAPI/Version_syntax_changes
>>
>> --
>> Best regards,
>> Michał Górny
>> <http://dev.gentoo.org/~mgorny/>
>
> I also like the idea of moving the operator as it's more consistent
> and opens new doors to other solutions.
>
> As for the use of operator & and |, they're quite good, but I'd prefer
> the use of Gmail's style where expressions placed in () are processed
> with AND, and expressions placed inside {} are processed with OR:
>
> dev-foo/bar[>=1.3&<1.5]        dev-foo/bar(>=1.3 <1.5)
> dev-foo/bar[>=1.3&<1.5&!=1.4.1]        dev-foo/bar(>=1.3 <1.5 !=1.4.1)
> dev-foo/bar[<1.1|>=1.5]        dev-foo/bar{<1.1 >=1.5}
> dev-foo/bar[=1.1*|=1.3*|>=1.5]        dev-foo/bar{=1.1* =1.3* >=1.5}
>
> I find it more readable.  The former looks too compressed.

I should also add that we can allow slots and repositories in the expressions:

dev-foo/bar{:1.3 :1.4 :1.5}  ## Solves "A. Range dependencies vs slotting"
dev-foo/bar(:1.6 {::local ::devel})  ## Especially useful in
/etc/portage/package.{keywords,mask}

Along with it, we should also drop the strict order of the slot,
version, and repo expressions (just change it to "recommended").  It
makes things more flexible and makes it easier for the parser to be
implemented.

Arithmetic ranges on the other hand should only be in the form of
being "inclusive" in both ends, and not exclusive in any.  Not only is
it simpler; it is also easier to parse.  There's also no need to use
special grouping operators like {}.  E.g. 1.3..1.5.  Grouping is only
necessary if the form would cause other possible conflicts, where in
that case (1.3..1.5) and {1.3..1.5} should just be the same, unless
there would be more added expressions in the group.

-- 
konsolebox