> On 17 May 2018, at 11:02, Joerg Schilling
> <joerg.schill...@fokus.fraunhofer.de> wrote:
> Hans Åberg <haber...@telia.com> wrote:
>>>> |I asked a person who speaks japanese and he told me that
>>>> | "\u4e00\u4e8c\u4e09"
>>>> |is similar to
>>>> | "one two three"
>>>> |and this is not used for computing.
>>>> If i recall correctly this has been discussed already; if not here
>>>> then on the Unicode list. Unicode brings quite a lot of
>>>> codepoints, like CIRCLED DIGIT ONE, PARENTHESIZED DIGIT ONE, DIGIT
>>>> ONE FULL STOP etc. All these are marked "No", and i think the
>>>> discussion concluded that they should not be taken into account
>>>> when converting strings to numbers.
>> The intent may be that the value of the digit character c can be computed by
>> the expression c - '0' when >= 0 and <= 9, and is otherwise a non-digit.
>> Then 'isdigit' and [[:digit:]] are tied to that, so it is impossible to use
>> any other decimal digits.
> This seems to be an important idea, as this japanese one two three
> is not in a contiguous order.
It provides an efficient implementation, important on earlier computers. The
UTF-8 article , "History", mentions that they struggled around 1992 to find
proposals for that providing efficient implementations.