[Distutils] 'markerlib' (environment markers) is ready

[Tarek Ziadé]

On 7/25/12 3:33 PM, Daniel Holth wrote:
> I'm happy with markerlib, my implementation of environment markers. In
> markerlib, a marker is a function
>
> def marker(environment=None, override=None)
>
> where environment is the environment and override updates the
> environment; if environment is None then it's the default environment.
> So marker(override={'python_version':'2.6'}) evaluates the marker with
> the python version changed to 2.6. The API is two functions compile()
> (recommended) and interpret() (compatible with packaging API).
>
> The implementation takes advantage of the fact that variables can
> contain "." at the interpreter level, and then implements markers as
> Python with only (Compare, BoolOp, Attribute, Name, Load, Str, cmpop,
> boolop) AST nodes allowed.
>
> On CPython 2.7 it is a little bit slower than the distutils2
> implementation for a single compilation+evaluation of a statement like
> "a == 'a' or b == 'b'" but is much faster for repeated evaluation. It
> works for Python >= 2.5. It has 100% code coverage.
>
> Would you be interested in folding this into packaging, or distribute
> (yes, the setuptools fork) since markers are needed to properly
> support .dist-info, perhaps as a different top-level name 'markers' or
> 'envmarkers'?
> _______________________________________________

cool !

+1


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