[Python-ideas] allow line break at operators

[Arnaud Delobelle]

On 18 September 2011 03:18, Steven D'Aprano <steve at pearwood.info> wrote:
> Arnaud Delobelle wrote:
>>
>> On 4 September 2011 23:39, Ben Finney <ben+python at benfinney.id.au> wrote:
>>>
>>> Ben Finney <ben+python at benfinney.id.au> writes:
>>>
>>>> MRAB <python at mrabarnett.plus.com> writes:
>>>>
>>>>> As well as still limiting a comment to a line, I'd also still limit
>>>>> a string literal (except a triple-quoted string literal) to a line.
>>>>
>>>> How many string literals do you count in the following statement? I
>>>> count one:
>>>>
>>>>    raise HoustonWeHaveAProblemError(
>>>>        "Lorem ipsum dolor sit amet,"
>>>>        " consectetur adipiscing elit.")
>>>
>>> The Python compiler agrees with me:
>>>
>>>   >>> import dis
>>>   >>> def foo():
>>>   ...     raise ValueError(
>>>   ...         "Lorem ipsum dolor sit amet,"
>>>   ...         " consectetur adipiscing elit.")
>>>   ...
>>>   >>> dis.dis(foo)
>>>     2           0 LOAD_GLOBAL              0 (ValueError)
>>>
>>>     3           3 LOAD_CONST               1 ('Lorem ipsum dolor sit
>>> amet, consectetur adipiscing elit.')
>>>                 6 CALL_FUNCTION            1
>>>                 9 RAISE_VARARGS            1
>>>                12 LOAD_CONST               0 (None)
>>>                15 RETURN_VALUE
>
>
> Compile-time implicit concatenation of string literals is a guarantee of the
> language. Any Python implementation must do that, going back to at least
> CPython 1.5 and possibly older.
>
>
>> The code object says that there's one string constant in the compiled
>> function.  It says nothing (and knows nothing) about the number of
>> string literals that made up this string.  In the following, how many
>> string literals can you see?
>>
>>
>>>>> def bar(): return "a" + "b"
>>
>> ...
>>
>> Now let's look at the code object:
>>
>>
>>>>> dis.dis(bar)
>>
>>  1           0 LOAD_CONST               3 ('ab')
>>              3 RETURN_VALUE
>
>
> I'm not entirely sure I understand your point there.

My point is that looking at the number of string constants in compiled
code does not tell you the number of string literals in the source
code.  I thought this was clear from the context of my reply to Ben
(see quoted messages above).

-- 
Arnaud