[Kimchi-devel] [PATCH V5] add a make check-local command to verify the i18n string formatting

[Sheldon]

On 04/10/2014 03:47 PM, Zhou Zheng Sheng wrote:
> on 2014/04/08 21:18, shaohef at linux.vnet.ibm.com wrote:
>> +PATTERN = re.compile("%\([^\)]*\)[#0\-\+ ]?(\d+|\*)?(\.(\d+|\*))?"
>> +                     "[lLh]?[cdeEfFgGioursxX%]")
>> +BAD_PATTERN = re.compile("%\([^\)]*\)")
> There are some problems in the regular expressions.
>
> The first problem is that "\" is a special character in Python string.
> For example, we all know "\" gives a special meaning to "\n" and "\t".
> If we want to use it in a regular expression, we have to escape itself,
> for example re.compile("%\\(\\)"). This is tedious and error-prone.
> Usually we just use a prefix "r" before the string literal to stop
> Python from translating "\", for example, re.compile(r"%\(\)").
>
> The second problem is that "+", "*", "(", ")" automatically lose their
> special meaning inside "[ ]", we can use them directly in "[ ]".
>
> The third problem is that we should comment each part of a complicated
> regular expression.
>
> As a result, I suggest the following the regular expression.
>
> # Match all conversion specifier with mapping key
> PATTERN = re.compile(r'''%\([^)]+\)  # Mapping key
>                           [#0\-+]?  # Conversion flags (optional)
>                           (\d+|\*)?  # Minimum field width (optional)
>                           (\.(\d+|\*))?  # Precision (optional)
>                           [lLh]?  # Length modifier (optional)
>                           [cdeEfFgGioursxX%]  # Conversion type''',
>                      re.VERBOSE)
> BAD_PATTERN = re.compile(r"%\([^)]*?\)")
>
> Notice I drop the space from the conversion flags, and leave only "#",
> "0", "-" and "+". It is fully legal for someone to write the following,
>    "%(k) done" % {"k": 100}
> and the result is
>    ' 100one'
>
> This is because Python interpreters the space between "%(k)" and "done"
> as the conversion flag, then Python eats "d" from "done" as the
> conversion type. Though it's legal, it's error prone. So I think it's
> better not to support this rare usage of space in the conversion flags,
> and report it as error.
>
>
ACK.

-- 
Thanks and best regards!

Sheldon Feng(冯少合)<shaohef at linux.vnet.ibm.com>
IBM Linux Technology Center