On 11 November 2015 at 16:11, Robert Collins email@example.com 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 | firstname.lastname@example.org | Brisbane, Australia