[Python-ideas] Implicit string literal concatenation considered harmful?

[Ron Adam]

On 05/16/2013 12:38 PM, MRAB wrote:
>> I like the \ idea because it's clearly syntax and not an operator, but
>> the fact that it doesn't work with comments is annoying since one reason
>> to break a string is to insert comments. I don't like that spaces after
>> the \ are not allowed because trailing spaces are invisible to me but
>> not to the parser. So what if the rule for trailing \ was changed to:
>>
>>     The \ continuation character may be followed by white space and a
>>     comment. If a comment is present, there must be at least one
>>     whitespace character between the \ and the comment.
>>
>>
> Why do you say """there must be at least one whitespace character
> between the \ and the comment"""?


I'd like comments after a line continuation also.

There is an issue with it in strings.  The tokenizer uses the '\'+'\n' as a 
line continuation, rather than a single '\'.  By doing that, it can handle 
line continuations on any line exactly the same.

 >>> "This is a backslash \, and this\
...  line is continued also."
'This is a backslash \\, and this line is continued also.'

The \ is also used as a string escape sequence character also.


Outside of strings the '\' anywhere except at the end of a line is an 
error.  So we can do that without any issues with previous code.  But we 
need to not change it's behaviour between quotes.

Cheers

Ron