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Groups > comp.lang.python > #88084
| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: A simple single line, triple-quoted comment is giving syntax error. Why? |
| Date | 2015-03-26 19:54 +0100 |
| Organization | PointedEars Software (PES) |
| Message-ID | <1823599.Pr2V0MPR6q@PointedEars.de> (permalink) |
| References | (5 earlier) <mailman.52.1426997516.10327.python-list@python.org> <1504323.jUKfeKbQsP@PointedEars.de> <mailman.181.1427346636.10327.python-list@python.org> <2362875.FIK8ImHTJA@PointedEars.de> <mailman.211.1427394586.10327.python-list@python.org> |
Ian Kelly wrote:
> […] Thomas 'PointedEars' Lahn […] wrote:
>> Ian Kelly wrote:
>>> What the grammar that you quoted from shows is that STRING+ is an
>>> expression. The individual STRINGs of a STRING+ are not expressions,
>>> except to the extent that they can be parsed in isolation as a
>>> STRING+.
>> How did you get that idea? STRING+ means one or more consecutive STRING
>> tokens (ignoring whitespace in-between), which means one or more
>> consecutive string literals. A (single) string literal definitely is an
>> expression as it can be produced with the “expr” goal symbol of the
>> Python grammar (given there in a flavor of EBNF).
>
> Yes, that's what I was referring to in my parenthetical "except..." above.
Your “except” is contradictory to the rest of what you said, at best.
> What I mean is that if you construct a parse tree of "foo" "bar" using
> that grammar, it looks like this:
>
> expr
> |
> STRING+
> / \
> STRING STRING
> […]
>
> There is only one expr node, and it contains both STRING tokens.
Prove it.
But be warned: Neither would prove that a string literal is not an
expression. Because you did not consider the most simple variant of an AST
(or subtree) according to this grammar:
expr
|
STRING
Again, “STRING+” does _not_ mean “STRING STRING STRING*”; it means “STRING
STRING*”. The second and following STRINGs are *optional*.
>> […] in the used flavour of EBNF the unquoted “+” following a goal symbol
>> clearly means the occurrence of *at least one* of the immediately
>> preceding symbol, meaning either one *or more than one*.
>
> It means one or more *tokens*, not one or more literals.
Utter nonsense. Have you ever written a parser? (I have.) A literal *is*
a token. Whether two consecutive tokens end up as the same *node* in an AST
is a *different* issue (that, again, was _not_ debated).
--
PointedEars
Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.
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A simple single line, triple-quoted comment is giving syntax error. Why? Aditya Raj Bhatt <adityarajbhatt@gmail.com> - 2015-03-18 10:46 -0700
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Laurent Pointal <laurent.pointal@laposte.net> - 2015-03-18 19:04 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Laurent Pointal <laurent.pointal@laposte.net> - 2015-03-18 19:06 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-18 20:53 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-18 20:56 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Terry Reedy <tjreedy@udel.edu> - 2015-03-18 17:47 -0400
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-19 09:58 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Chris Angelico <rosuav@gmail.com> - 2015-03-19 10:23 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Aditya Raj Bhatt <adityarajbhatt@gmail.com> - 2015-03-18 11:23 -0700
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Igor Korot <ikorot01@gmail.com> - 2015-03-18 14:45 -0400
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Laurent Pointal <laurent.pointal@laposte.net> - 2015-03-18 20:08 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Tim Roberts <timr@probo.com> - 2015-03-28 16:34 -0700
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-18 21:21 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Tim Chase <python.list@tim.thechases.com> - 2015-03-18 13:15 -0500
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ben Finney <ben+python@benfinney.id.au> - 2015-03-19 11:06 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Denis McMahon <denismfmcmahon@gmail.com> - 2015-03-19 00:53 +0000
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-22 04:14 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Chris Angelico <rosuav@gmail.com> - 2015-03-22 14:36 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-22 04:49 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Chris Angelico <rosuav@gmail.com> - 2015-03-22 15:11 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-26 05:35 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 23:09 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-26 17:45 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 12:29 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-26 19:54 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 17:27 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-28 19:20 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-29 01:56 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-29 12:41 +0200
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-31 01:23 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? sohcahtoa82@gmail.com - 2015-03-31 16:10 -0700
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Chris Angelico <rosuav@gmail.com> - 2015-04-01 10:36 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-31 17:43 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-04-02 23:31 +0200
Re: A simple single line, triple-quoted comment is giving syntax error. Why? sohcahtoa82@gmail.com - 2015-04-02 15:26 -0700
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-02 18:21 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-03 16:40 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Chris Angelico <rosuav@gmail.com> - 2015-04-03 16:57 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Marko Rauhamaa <marko@pacujo.net> - 2015-04-03 10:13 +0300
r"\"" ??? (was A simple single line, triple-quoted comment) Rustom Mody <rustompmody@gmail.com> - 2015-04-03 05:52 -0700
Re: r"\"" ??? (was A simple single line, triple-quoted comment) Chris Angelico <rosuav@gmail.com> - 2015-04-04 01:40 +1100
Re: r"\"" ??? (was A simple single line, triple-quoted comment) Rustom Mody <rustompmody@gmail.com> - 2015-04-03 08:14 -0700
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-03 09:25 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-03 00:40 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-03-27 11:43 +1300
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-28 19:06 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 12:32 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-26 19:56 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-27 10:15 +1100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Tim Chase <python.list@tim.thechases.com> - 2015-03-26 18:47 -0500
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 19:38 -0600
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Marko Rauhamaa <marko@pacujo.net> - 2015-03-27 07:34 +0200
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Dave Angel <davea@davea.name> - 2015-03-26 01:23 -0400
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-26 18:25 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-03-26 18:30 +0100
Re: A simple single line, triple-quoted comment is giving syntax error. Why? Marko Rauhamaa <marko@pacujo.net> - 2015-03-22 12:00 +0200
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