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Groups > comp.lang.python > #93701
| From | Mark Lawrence <breamoreboy@yahoo.co.uk> |
|---|---|
| Subject | Re: 0 + not 0 |
| Date | 2015-07-11 21:05 +0100 |
| References | <01ec6551-1f40-42b0-9406-036030591519@googlegroups.com> <mailman.420.1436621919.3674.python-list@python.org> <not-20150711180044@ram.dialup.fu-berlin.de> <CALwzidm4QvBQ_4XZsuLTw8rzWmd3trT4W+P3XcH0CBWb7Vyb1g@mail.gmail.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.432.1436645136.3674.python-list@python.org> (permalink) |
On 11/07/2015 17:56, Ian Kelly wrote: > On Sat, Jul 11, 2015 at 10:02 AM, Stefan Ram <ram@zedat.fu-berlin.de> wrote: >> I look at Python 3.4.3: >> >> a_expr ::= m_expr | a_expr "+" m_expr | a_expr "-" m_expr >> >> So, »not 0« must be an »m_expr« when used as the right operand of »+«. >> >> m_expr ::= u_expr | m_expr "*" u_expr | m_expr "//" u_expr | m_expr "/" u_expr | m_expr "%" u_expr >> u_expr ::= power | "-" u_expr | "+" u_expr | "~" u_expr >> power ::= primary ["**" u_expr] >> primary ::= atom | attributeref | subscription | slicing | call >> atom ::= identifier | literal | enclosure >> enclosure ::= parenth_form | list_display | dict_display | set_display | generator_expression | yield_atom >> >> How can there be a »not«? >> >> »not« is used in >> >> not_test ::= comparison | "not" not_test >> and_test ::= not_test | and_test "and" not_test >> or_test ::= and_test | or_test "or" and_test >> conditional_expression ::= or_test ["if" or_test "else" expression] >> expression_nocond ::= or_test | lambda_expr_nocond >> expression ::= conditional_expression | lambda_expr >> >> , but an »expression« is not an »m_expr«. > > I must concur. The grammar as written does not actually produce 1 + > not 0. I think it's still worthwhile opening a bug, because the > behavior is surprising and possibly not intentional. > http://bugs.python.org/issue24612 -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence
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0 + not 0 candide <c.candide@laposte.net> - 2015-07-11 03:26 -0700
Re: 0 + not 0 Chris Angelico <rosuav@gmail.com> - 2015-07-11 20:38 +1000
Re: 0 + not 0 Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2015-07-11 12:38 +0200
Re: 0 + not 0 Luuk <luuk@invalid.lan> - 2015-07-11 13:12 +0200
Re: 0 + not 0 Chris Angelico <rosuav@gmail.com> - 2015-07-11 21:20 +1000
Re: 0 + not 0 Luuk <luuk@invalid.lan> - 2015-07-11 13:30 +0200
Re: 0 + not 0 candide <c.candide@laposte.net> - 2015-07-11 04:54 -0700
Re: 0 + not 0 Chris Angelico <rosuav@gmail.com> - 2015-07-11 22:05 +1000
Re: 0 + not 0 candide <c.candide@laposte.net> - 2015-07-11 06:22 -0700
Re: 0 + not 0 candide <c.candide@laposte.net> - 2015-07-11 04:48 -0700
Re: 0 + not 0 random832@fastmail.us - 2015-07-11 16:46 -0400
Re: 0 + not 0 Serhiy Storchaka <storchaka@gmail.com> - 2015-07-11 16:38 +0300
Re: 0 + not 0 candide <c.candide@laposte.net> - 2015-07-11 08:07 -0700
Re: 0 + not 0 MRAB <python@mrabarnett.plus.com> - 2015-07-11 17:20 +0100
Re: 0 + not 0 Ian Kelly <ian.g.kelly@gmail.com> - 2015-07-11 10:56 -0600
Re: 0 + not 0 Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-07-12 18:12 +1200
Re: 0 + not 0 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-07-11 21:05 +0100
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