[gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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I would like to suggest introduction of support for PYTHON_DEPEND variable, which
would be a better replacement for NEED_PYTHON variable. NEED_PYTHON variable
does not allow to specify that e.g. only versions of Python 2 are accepted.
(Eventually PYTHON_DEPEND variable will have to be set only in ebuilds of packages
not supporting installation for multiple versions of Python.)

Suggested syntax:
  PYTHON_DEPEND="[USE_flag?] <X[:[Y][:[Z]]]> [X[:[Y][:[Z]]]]"
    <required_component>, [optional_component]
    X - Major version of Python ('2' or '3') or '*'.
    Y - Minimal version of Python in the form of ${major_version}.${minor_version}.
    Z - Maximal version of Python in the form of ${major_version}.${minor_version}.
        It will be probably very rarely used.

Examples:
  PYTHON_DEPEND="2"
    Dependency on any version of Python 2.

  PYTHON_DEPEND="2:2.5"
    Dependency on Python 2.7, 2.6 or 2.5.

  PYTHON_DEPEND="*:2.6"
    Dependency on Python 3.2, 3.1, 3.0, 2.7 or 2.6.

  PYTHON_DEPEND="2:2.7 3:3.1"
    Dependency on Python 3.2, 3.1 or 2.7.

  PYTHON_DEPEND="2:2.5:2.6"
    Dependency on Python 2.6 or 2.5.

  PYTHON_DEPEND="2::2.6"
    Dependency on Python 2.6, 2.5 or 2.4.

  PYTHON_DEPEND="python? 2"
    Dependency on any version of Python 2 when "python" USE flag is enabled.

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Sebastian Pipping]

On 01/10/10 09:29, Arfrever Frehtes Taifersar Arahesis wrote:
> I would like to suggest introduction of support for PYTHON_DEPEND variable, which
> would be a better replacement for NEED_PYTHON variable. NEED_PYTHON variable
> does not allow to specify that e.g. only versions of Python 2 are accepted.
> (Eventually PYTHON_DEPEND variable will have to be set only in ebuilds of packages
> not supporting installation for multiple versions of Python.)
> 
> Suggested syntax:
>   PYTHON_DEPEND="[USE_flag?] <X[:[Y][:[Z]]]> [X[:[Y][:[Z]]]]"
>     <required_component>, [optional_component]
>     X - Major version of Python ('2' or '3') or '*'.
>     Y - Minimal version of Python in the form of ${major_version}.${minor_version}.
>     Z - Maximal version of Python in the form of ${major_version}.${minor_version}.
>         It will be probably very rarely used.
> 
> Examples:
>   PYTHON_DEPEND="2"
>     Dependency on any version of Python 2.
> 
>   PYTHON_DEPEND="2:2.5"
>     Dependency on Python 2.7, 2.6 or 2.5.
> 
>   PYTHON_DEPEND="*:2.6"
>     Dependency on Python 3.2, 3.1, 3.0, 2.7 or 2.6.
> 
>   PYTHON_DEPEND="2:2.7 3:3.1"
>     Dependency on Python 3.2, 3.1 or 2.7.
> 
>   PYTHON_DEPEND="2:2.5:2.6"
>     Dependency on Python 2.6 or 2.5.
> 
>   PYTHON_DEPEND="2::2.6"
>     Dependency on Python 2.6, 2.5 or 2.4.
> 
>   PYTHON_DEPEND="python? 2"
>     Dependency on any version of Python 2 when "python" USE flag is enabled.
> 

While I don't object improvements or changes on that front at all:

 - How are SUPPORT_PYTHON_ABIS and RESTRICT_PYTHON_ABIS affected
   by NEED_PYTHON now and by PYTHON_DEPEND in the future?

 - The proposed approach doesn't look intuitive to me from a quick
   view, sorry:  Neither the examples nor the grammar.  I didn't give
   it that much time to be fair, though.



Sebastian

Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-10 19:41:55 Sebastian Pipping napisał(a):
> On 01/10/10 09:29, Arfrever Frehtes Taifersar Arahesis wrote:
> > I would like to suggest introduction of support for PYTHON_DEPEND variable, which
> > would be a better replacement for NEED_PYTHON variable. NEED_PYTHON variable
> > does not allow to specify that e.g. only versions of Python 2 are accepted.
> > (Eventually PYTHON_DEPEND variable will have to be set only in ebuilds of packages
> > not supporting installation for multiple versions of Python.)
> > 
> > Suggested syntax:
> >   PYTHON_DEPEND="[USE_flag?] <X[:[Y][:[Z]]]> [X[:[Y][:[Z]]]]"
> >     <required_component>, [optional_component]
> >     X - Major version of Python ('2' or '3') or '*'.
> >     Y - Minimal version of Python in the form of ${major_version}.${minor_version}.
> >     Z - Maximal version of Python in the form of ${major_version}.${minor_version}.
> >         It will be probably very rarely used.
> > 
> > Examples:
> >   PYTHON_DEPEND="2"
> >     Dependency on any version of Python 2.
> > 
> >   PYTHON_DEPEND="2:2.5"
> >     Dependency on Python 2.7, 2.6 or 2.5.
> > 
> >   PYTHON_DEPEND="*:2.6"
> >     Dependency on Python 3.2, 3.1, 3.0, 2.7 or 2.6.
> > 
> >   PYTHON_DEPEND="2:2.7 3:3.1"
> >     Dependency on Python 3.2, 3.1 or 2.7.
> > 
> >   PYTHON_DEPEND="2:2.5:2.6"
> >     Dependency on Python 2.6 or 2.5.
> > 
> >   PYTHON_DEPEND="2::2.6"
> >     Dependency on Python 2.6, 2.5 or 2.4.
> > 
> >   PYTHON_DEPEND="python? 2"
> >     Dependency on any version of Python 2 when "python" USE flag is enabled.
> > 
> 
> While I don't object improvements or changes on that front at all:
> 
>  - How are SUPPORT_PYTHON_ABIS and RESTRICT_PYTHON_ABIS affected
>    by NEED_PYTHON now and by PYTHON_DEPEND in the future?

They aren't and won't be. PYTHON_DEPEND is designed mainly for packages
not supporting installation for multiple Python versions.

>  - The proposed approach doesn't look intuitive to me from a quick
>    view, sorry:  Neither the examples nor the grammar.  I didn't give
>    it that much time to be fair, though.

IMHO it's sufficiently intuitive :) .

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Sebastian Pipping]

>>>   PYTHON_DEPEND="2:2.5:2.6"
>>>     Dependency on Python 2.6 or 2.5.

The colon (':') has two different semantics here.
This violates "different things should look different".

You are designing a language here.  Please improve the proposal.



Sebastian

Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-11 04:55:02 Sebastian Pipping napisał(a):
> >>>   PYTHON_DEPEND="2:2.5:2.6"
> >>>     Dependency on Python 2.6 or 2.5.
> 
> The colon (':') has two different semantics here.

The colon is only separator of components, so it has the same semantic.
Each component has strictly defined meaning.

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Sebastian Pipping]

On 01/11/10 09:47, Arfrever Frehtes Taifersar Arahesis wrote:
> 2010-01-11 04:55:02 Sebastian Pipping napisał(a):
>>>>>   PYTHON_DEPEND="2:2.5:2.6"
>>>>>     Dependency on Python 2.6 or 2.5.
>>
>> The colon (':') has two different semantics here.
> 
> The colon is only separator of components, so it has the same semantic.
> Each component has strictly defined meaning.

The first ':' is a slot colon while the second one is a from-to colon. I
fail to see how that is the same semantic.

Also, in normal dependency notation the slot is suffix-like (e.g.
package:2) whereas in this syntax it's prefix-like - the opposite.
Wouldn't it be more intuitive to make suffix-like use of it?

Looking from another angle there is range syntax being used for
kernel-check already.  It looks like this:

  [linux >=2.6.16 <2.6.31]

(examples on <http://dev.gentoo.org/~asym/guide.xml>)

Maybe you could adjust that to your needs.  I'm not sure where that
syntax is defined but afair rbu should be a good contact on that subject
(Robert?).



Sebastian

Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Fabian Groffen]

On 10-01-2010 09:29:28 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> I would like to suggest introduction of support for PYTHON_DEPEND variable, which
> would be a better replacement for NEED_PYTHON variable. NEED_PYTHON variable
> does not allow to specify that e.g. only versions of Python 2 are accepted.
> (Eventually PYTHON_DEPEND variable will have to be set only in ebuilds of packages
> not supporting installation for multiple versions of Python.)

Can you explain the intended use of this variable, and why normal DEPEND
is not sufficient?


-- 
Fabian Groffen
Gentoo on a different level

Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-10 21:56:01 Fabian Groffen napisał(a):
> On 10-01-2010 09:29:28 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> > I would like to suggest introduction of support for PYTHON_DEPEND variable, which
> > would be a better replacement for NEED_PYTHON variable. NEED_PYTHON variable
> > does not allow to specify that e.g. only versions of Python 2 are accepted.
> > (Eventually PYTHON_DEPEND variable will have to be set only in ebuilds of packages
> > not supporting installation for multiple versions of Python.)
> 
> Can you explain the intended use of this variable, and why normal DEPEND
> is not sufficient?

PYTHON_DEPEND is intented to simplify specification of dependency on Python.

PYTHON_DEPEND="2:2.5" is shorter than:
DEPEND="|| ( =dev-lang/python-2.7* =dev-lang/python-2.6* =dev-lang/python-2.5* )"

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Fabian Groffen]

On 11-01-2010 01:25:45 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> > Can you explain the intended use of this variable, and why normal DEPEND
> > is not sufficient?
> 
> PYTHON_DEPEND is intented to simplify specification of dependency on Python.
> 
> PYTHON_DEPEND="2:2.5" is shorter than:
> DEPEND="|| ( =dev-lang/python-2.7* =dev-lang/python-2.6* =dev-lang/python-2.5* )"

So if there is enough space to express the dependency with the current
syntax, is it worth introducing a new shorthand for it then?

Also for this example, why does 2:2.5 expand to 2.7, 2.6 and 2.5?  I
would have expected 2.0 ... 2.5.  Maybe the language isn't as intuitive
then as Sebastian pointed out.


-- 
Fabian Groffen
Gentoo on a different level

[gentoo-dev] Re: PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Duncan]

Fabian Groffen posted on Mon, 11 Jan 2010 08:50:30 +0100 as excerpted:

> On 11-01-2010 01:25:45 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
>> > Can you explain the intended use of this variable, and why normal
>> > DEPEND is not sufficient?
>> 
>> PYTHON_DEPEND is intented to simplify specification of dependency on
>> Python.
>> 
>> PYTHON_DEPEND="2:2.5" is shorter than: DEPEND="|| (
>> =dev-lang/python-2.7* =dev-lang/python-2.6* =dev-lang/python-2.5* )"
> 
> So if there is enough space to express the dependency with the current
> syntax, is it worth introducing a new shorthand for it then?
> 
> Also for this example, why does 2:2.5 expand to 2.7, 2.6 and 2.5?  I
> would have expected 2.0 ... 2.5.  Maybe the language isn't as intuitive
> then as Sebastian pointed out.

Initially intuitive, perhaps not, but reasonably easy after reading the 
explanation:

The first position is major python version, the second if present, 
minimal version (within that major), so it can be read as =>version, the 
third if present, maximum version (within that major), so it can be read 
as <=.

Thus, the above "2:2.5" means major version 2, minimal version 2.5 (no 
maximum version within that major), so 2.5+.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

Re: [gentoo-dev] Re: PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Fabian Groffen]

On 11-01-2010 08:29:32 +0000, Duncan wrote:
> Fabian Groffen posted on Mon, 11 Jan 2010 08:50:30 +0100 as excerpted:
> 
> > On 11-01-2010 01:25:45 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> >> > Can you explain the intended use of this variable, and why normal
> >> > DEPEND is not sufficient?
> >> 
> >> PYTHON_DEPEND is intented to simplify specification of dependency on
> >> Python.
> >> 
> >> PYTHON_DEPEND="2:2.5" is shorter than: DEPEND="|| (
> >> =dev-lang/python-2.7* =dev-lang/python-2.6* =dev-lang/python-2.5* )"
> > 
> > So if there is enough space to express the dependency with the current
> > syntax, is it worth introducing a new shorthand for it then?
> > 
> > Also for this example, why does 2:2.5 expand to 2.7, 2.6 and 2.5?  I
> > would have expected 2.0 ... 2.5.  Maybe the language isn't as intuitive
> > then as Sebastian pointed out.
> 
> Initially intuitive, perhaps not, but reasonably easy after reading the 
> explanation:
> 
> The first position is major python version, the second if present, 
> minimal version (within that major), so it can be read as =>version, the 
> third if present, maximum version (within that major), so it can be read 
> as <=.
> 
> Thus, the above "2:2.5" means major version 2, minimal version 2.5 (no 
> maximum version within that major), so 2.5+.

what's wrong with ">=2.5 && <3.0" then?


-- 
Fabian Groffen
Gentoo on a different level

Re: [gentoo-dev] Re: PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-11 11:14:40 Fabian Groffen napisał(a):
> On 11-01-2010 08:29:32 +0000, Duncan wrote:
> > Fabian Groffen posted on Mon, 11 Jan 2010 08:50:30 +0100 as excerpted:
> > 
> > > On 11-01-2010 01:25:45 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> > >> > Can you explain the intended use of this variable, and why normal
> > >> > DEPEND is not sufficient?
> > >> 
> > >> PYTHON_DEPEND is intented to simplify specification of dependency on
> > >> Python.
> > >> 
> > >> PYTHON_DEPEND="2:2.5" is shorter than: DEPEND="|| (
> > >> =dev-lang/python-2.7* =dev-lang/python-2.6* =dev-lang/python-2.5* )"
> > > 
> > > So if there is enough space to express the dependency with the current
> > > syntax, is it worth introducing a new shorthand for it then?
> > > 
> > > Also for this example, why does 2:2.5 expand to 2.7, 2.6 and 2.5?  I
> > > would have expected 2.0 ... 2.5.  Maybe the language isn't as intuitive
> > > then as Sebastian pointed out.
> > 
> > Initially intuitive, perhaps not, but reasonably easy after reading the 
> > explanation:
> > 
> > The first position is major python version, the second if present, 
> > minimal version (within that major), so it can be read as =>version, the 
> > third if present, maximum version (within that major), so it can be read 
> > as <=.
> > 
> > Thus, the above "2:2.5" means major version 2, minimal version 2.5 (no 
> > maximum version within that major), so 2.5+.
> 
> what's wrong with ">=2.5 && <3.0" then?

It's too long and harder to parse.

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-11 08:50:30 Fabian Groffen napisał(a):
> On 11-01-2010 01:25:45 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> > > Can you explain the intended use of this variable, and why normal DEPEND
> > > is not sufficient?
> > 
> > PYTHON_DEPEND is intented to simplify specification of dependency on Python.
> > 
> > PYTHON_DEPEND="2:2.5" is shorter than:
> > DEPEND="|| ( =dev-lang/python-2.7* =dev-lang/python-2.6* =dev-lang/python-2.5* )"
> 
> So if there is enough space to express the dependency with the current
> syntax, is it worth introducing a new shorthand for it then?

Some eclasses already support some shorthands for specification of some
dependencies (e.g. need_apache2() in depend.apache.eclass).
As maintainer of some packages depending on Python, I express interest in
possibility of brief specification of dependency on Python. I won't be
enforcing using of this variable for developers, who want to directly
specify dependencies in {,R}DEPEND.

> Also for this example, why does 2:2.5 expand to 2.7, 2.6 and 2.5?  I
> would have expected 2.0 ... 2.5.

The first component ('2') specifies the group of accepted versions.
The second component ('2.5') specifies the minimal accepted version inside
this group. ('2:2.5' is identical to '2:2.5:'.)

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Gilles Dartiguelongue]

It looks like what you really want is a ranged dependencies. From the
look of it though I have to second the "it does not seem intuitive"
opinion as it gives another meaning to the slot syntax marker (':').
Other than that, it seems like a worthy addition to the eclass.

-- 
Gilles Dartiguelongue <eva@gentoo.org>
Gentoo

Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-11 12:04:05 Gilles Dartiguelongue napisał(a):
> It looks like what you really want is a ranged dependencies.

Dependencies specified in PYTHON_DEPEND can be expanded into ranged
dependencies in EAPIs, which support ranged dependencies.

-- 
Arfrever Frehtes Taifersar Arahesis

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Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Maciej Mrozowski]

On Monday 11 of January 2010 01:25:45 Arfrever Frehtes Taifersar Arahesis 
wrote:
> 2010-01-10 21:56:01 Fabian Groffen napisał(a):
> > On 10-01-2010 09:29:28 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> > > I would like to suggest introduction of support for PYTHON_DEPEND
> > > variable, which would be a better replacement for NEED_PYTHON
> > > variable. NEED_PYTHON variable does not allow to specify that e.g.
> > > only versions of Python 2 are accepted. (Eventually PYTHON_DEPEND
> > > variable will have to be set only in ebuilds of packages not
> > > supporting installation for multiple versions of Python.)
> > 
> > Can you explain the intended use of this variable, and why normal DEPEND
> > is not sufficient?
> 
> PYTHON_DEPEND is intented to simplify specification of dependency on
> Python.
> 
> PYTHON_DEPEND="2:2.5" is shorter than:
> DEPEND="|| ( =dev-lang/python-2.7* =dev-lang/python-2.6*
> =dev-lang/python-2.5* )"

Doesn't that accidentally mean that dev-lang/python is improperly slotted and 
all 2.x releases should be slotted with :2?
So that dependency string would look like:
DEPEND=">=dev-lang/python-2.5.0:2"

-- 
regards
MM

Re: [gentoo-dev] PYTHON_DEPEND - Suggested replacement for NEED_PYTHON

[Arfrever Frehtes Taifersar Arahesis]

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2010-01-11 11:14:11 Maciej Mrozowski napisał(a):
> On Monday 11 of January 2010 01:25:45 Arfrever Frehtes Taifersar Arahesis 
> wrote:
> > 2010-01-10 21:56:01 Fabian Groffen napisał(a):
> > > On 10-01-2010 09:29:28 +0100, Arfrever Frehtes Taifersar Arahesis wrote:
> > > > I would like to suggest introduction of support for PYTHON_DEPEND
> > > > variable, which would be a better replacement for NEED_PYTHON
> > > > variable. NEED_PYTHON variable does not allow to specify that e.g.
> > > > only versions of Python 2 are accepted. (Eventually PYTHON_DEPEND
> > > > variable will have to be set only in ebuilds of packages not
> > > > supporting installation for multiple versions of Python.)
> > > 
> > > Can you explain the intended use of this variable, and why normal DEPEND
> > > is not sufficient?
> > 
> > PYTHON_DEPEND is intented to simplify specification of dependency on
> > Python.
> > 
> > PYTHON_DEPEND="2:2.5" is shorter than:
> > DEPEND="|| ( =dev-lang/python-2.7* =dev-lang/python-2.6*
> > =dev-lang/python-2.5* )"
> 
> Doesn't that accidentally mean that dev-lang/python is improperly slotted and 
> all 2.x releases should be slotted with :2?

dev-lang/python is properly slotted.

-- 
Arfrever Frehtes Taifersar Arahesis

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