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Groups > comp.lang.java.programmer > #26109

Re: Why No Supplemental Characters In Character Literals?

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On 04-02-2011 12:10, Mike Schilling wrote:
>
>
> "Arne Vajhøj" <arne@vajhoej.dk> wrote in message
> news:4d4c2019$0$23753$14726298@news.sunsite.dk...
>> On 04-02-2011 01:59, Lawrence D'Oliveiro wrote:
>>> In message<iig6j2$dul$2@news.albasani.net>, Lew wrote:
>>>> On 02/04/2011 12:59 AM, Lawrence D'Oliveiro wrote:
>>>>> Why was it decreed in the language spec that characters beyond
>>>>> U+FFFF are
>>>>> not allowed in character literals, when they are allowed everywhere
>>>>> else
>>>>> (in string literals, in the program text, in character and string
>>>>> values
>>>>> etc)?
>>>>
>>>> Because a 'char' type holds only 16 bits.
>>>
>>> No it doesn’t. Otherwise you wouldn’t be allowed supplementary
>>> characters in
>>> character and string values. Which you are.
>>
>> It is very clearly specified that a Java char is 16 bit.
>>
>> You can't have the codepoints above U+FFFF in a char.
>>
>> You can have them in a string but then they actually takes
>> two chars in that string.
>>
>> It is rather messy.
>>
>> If you look at the Java docs for String class you will see:
>>
>> charAt & codePointAt
>> length & codePointCount
>>
>> which is not a nice API.
>>
>> But since codepoints above U+FFFF was added after the String
>> class was defined, then the options on how to handle it were
>> pretty limited.
>
> The sticky issue is, I think, that chars were defined as 16-bit. If that
> had been left undefined, they could have been extended to 24 bits, which
> would make things nice and regular again.

Yes.

But having specific bit lengths for all types was huge jump
forward compared to C89 regarding predictability of what code
would do.

Arne

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Re: Why No Supplemental Characters In Character Literals? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-02-04 19:59 +1300
  Re: Why No Supplemental Characters In Character Literals? "Mike Schilling" <mscottschilling@hotmail.com> - 2011-02-04 17:02 -0800
    Re: Why No Supplemental Characters In Character Literals? Ken Wesson <kwesson@gmail.com> - 2011-02-05 04:21 +0100
  Re: Why No Supplemental Characters In Character Literals? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-04 19:05 -0500
    Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 19:56 -0500
    Re: Why No Supplemental Characters In Character Literals? "Mike Schilling" <mscottschilling@hotmail.com> - 2011-02-04 16:37 -0800
  Re: Why No Supplemental Characters In Character Literals? "Mike Schilling" <mscottschilling@hotmail.com> - 2011-02-04 00:22 -0800
    Re: Why No Supplemental Characters In Character Literals? Roedy Green <see_website@mindprod.com.invalid> - 2011-02-04 15:03 -0800
    Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 18:04 -0500
    Re: Why No Supplemental Characters In Character Literals? Lew <noone@lewscanon.com> - 2011-02-04 07:49 -0500
    Re: Why No Supplemental Characters In Character Literals? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-02-05 11:26 +1300
  Re: Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-04 19:13 -0500
    Re: Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 20:08 -0500
  Re: Why No Supplemental Characters In Character Literals? Daniele Futtorovic <da.futt.news@laposte.net.invalid> - 2011-02-04 18:37 +0100
    Re: Why No Supplemental Characters In Character Literals? markspace <nospam@nowhere.com> - 2011-02-04 11:27 -0800
  Re: Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-04 17:28 -0500
  Re: Why No Supplemental Characters In Character Literals? "Mike Schilling" <mscottschilling@hotmail.com> - 2011-02-04 09:10 -0800
    Re: Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Roedy Green <see_website@mindprod.com.invalid> - 2011-02-04 15:22 -0800
      Re: Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 18:41 -0500
    Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 18:12 -0500
    Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Tom Anderson <twic@urchin.earth.li> - 2011-02-04 21:30 +0000
      Re: Efficient unicode string implementation was: Re: Why No Supplemental Characters In Character Literals? Ken Wesson <kwesson@gmail.com> - 2011-02-05 04:25 +0100
    Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 12:33 -0500
    Re: Why No Supplemental Characters In Character Literals? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-04 13:44 -0500
      Re: Why No Supplemental Characters In Character Literals? Roedy Green <see_website@mindprod.com.invalid> - 2011-02-04 15:08 -0800
  Re: Why No Supplemental Characters In Character Literals? Lew <lew@lewscanon.com> - 2011-02-04 12:43 -0800
  Re: Why No Supplemental Characters In Character Literals? Arne Vajhøj <arne@vajhoej.dk> - 2011-02-04 10:49 -0500
  Re: Why No Supplemental Characters In Character Literals? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-04 08:04 -0500

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