On 17/05/13 19:32, Christian Tismer wrote:
On 16.05.13 20:20, Chris Angelico wrote:
On Fri, May 17, 2013 at 4:14 AM, Bruce Leban <bruce@leapyear.org> wrote:
I'm not passionate about that detail if the rest of the proposal flies.
Spin that off as a separate thread, I think the change to the backslash rules stands alone. I would support it; allowing a line-continuation backslash to be followed by a comment is a Good Thing imo.
I don't think these matters should be discussed in separate threads.
They clearly should be in different threads. Line continuation is orthogonal to string continuation. You can have string concatenation on a single line: s = "Label:\t" r"Data containing \ backslashes" And you can have line continuations not involving strings: result = math.sin(23*theta) + cos(17*theta) - \ sin(3*theta**2)*cos(5*theta**3) Since the two things under discussion are independent, they should be discussed in different threads.
- implicit string concatenation becomes deprecated
-1 Implicit string concatenation is useful, and used by many people without problems.
- the backslash will allow comments, as proposed by Bruce
+0 It's not really that important these days. If you want comments, use brackets to group a multi-line expression.
- continuation of a string on the next line will later enforce the backslash.
I don't understand what this sentence means.
So repeating Bruce's example, the following would be allowed:
x = [ # THIS WOULD BE ALLOWED 'abc' \ 'def' \ # not the python keyword 'ghi' ]
The backslashes are redundant, since the square brackets already enable a multi-line expression.
And this would be an error:
x = [ # THIS WOULD BE AN ERROR 'abc' \ 'def' # a comment but no continuation \ 'ghi' ]
'\' would become kind of a line glue operator that becomes needed to merge the strings.
-1 since there are uses for concatenating strings on a single line.
I don't think that parentheses are superior for that. Parentheses are for expressions and they suggest expressions. Avoiding parentheses where they don't group parts of expressions is imo a good thing.
I don't understand this objection, since the parentheses are being used to group an expression. And they are being used to group expressions.
The reason why Python has grown the recommendation to use parentheses comes more from the absence of a good alternative.
Maybe so, but now that we have multi-line expressions inside brackets, the need for an alternative is much reduced. -- Steven