[Distutils] New PEP : dependency specification

Nick Coghlan ncoghlan at gmail.com
Wed Nov 11 01:41:36 EST 2015

On 11 November 2015 at 16:11, Robert Collins <robertc at robertcollins.net> wrote:
>  - fixed a bug in the marker language that happened somewhere in
> PEP-426. In PEP 345 markers were strictly 'LHS OP RHS' followed by AND
> or OR and then another marker expression. The grammar in PEP-426
> however allowed things like "(python_version) and
> (python_version=='2.7')" which I believe wasn't actually the intent -
> truthy values are not defined there. So the new grammar does not allow
> ("fred" and "bar") or other such things - and and or are exclusively
> between well defined expressions now.

Right, Vinay pointed out that the use of parentheses for grouping
wasn't well defined in 345, but instead grew implicitly out of their
evaluation as a Python subset. I attempted to fix that in 426, but
didn't intend to allow non-comparisons as operands for AND and OR.


Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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