Groups > comp.lang.java.programmer > #39449

Re: Character.isIdentifierIgnorable

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From	Arne Vajhøj <arne@vajhoej.dk>
Newsgroups	comp.lang.java.programmer
Subject	Re: Character.isIdentifierIgnorable
Date	Sat, 25 Apr 2020 13:01:18 -0400
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On 4/25/2020 12:57 PM, Arne Vajhøj wrote:
> On 4/24/2020 11:36 PM, Jeff Higgins wrote:
>> On 4/24/20 10:24 PM, Arne Vajhøj wrote:
>>> On 4/24/2020 8:37 PM, Jeff Higgins wrote:
>>>> On 4/24/20 8:29 PM, Arne Vajhøj wrote:
>>>>> I think we are in the far out corners of the language.
>>>>>
>>>> Well, yeah, but still.
>>>> And still leaves me questioning motivation for ignorable chars.
>>>
>>> We would need to find someone working at SUN back in the mid 90's
>>> to know.
>>>
>>> If I were to guess then somebody got the "smart" idea that
>>> the language should not distinguish between names where
>>> the difference could not be seen when type'd/cat'ed and
>>> then someone else later added the \uXXXX feature.
>>>
>> Maybe not that far back.
>>
>> from JLS-3.8 for JavaSE 9
>> Two identifiers are the same only if they are identical, that is, have 
>> the same
>> Unicode character for each letter or digit. Identifiers that have the 
>> same external
>> appearance may yet be different.
>>
>> from JLS-3.8 for JavaSE 10
>> Two identifiers are the same only if, after ignoring characters that are
>> ignorable, the identifiers have the same Unicode character for each 
>> letter
>> or digit. An ignorable character is a character for which the method
>> Character.isIdentifierIgnorable(int) returns true. Identifiers that 
>> have the
>> same external appearance may yet be different.
> 
> But Java 8 javac did ignore them??

So does Java 7 javac.

Java 6 javac gives me an error when trying to create the class file,
which likely means that it is not ignoring these characters.

Arne

Thread

Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 18:46 -0400
  Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-24 18:54 -0400
    Re: Character.isIdentifierIgnorable Martin Gregorie <martin@mydomain.invalid> - 2020-04-24 23:07 +0000
    Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 20:12 -0400
      Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-24 20:29 -0400
        Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 20:37 -0400
          Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-24 22:24 -0400
            Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 23:36 -0400
              Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-25 12:57 -0400
                Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-25 13:01 -0400
                Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-25 13:39 -0400
                Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-25 13:51 -0400
                Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-25 14:36 -0400
            Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 23:41 -0400
    Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 20:25 -0400
      Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-24 20:32 -0400
        Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-24 20:42 -0400
          Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-25 09:53 -0400
            Re: Character.isIdentifierIgnorable Arne Vajhøj <arne@vajhoej.dk> - 2020-04-25 12:55 -0400
              Re: Character.isIdentifierIgnorable Jeff Higgins <invalid@invalid.org> - 2020-04-25 13:43 -0400

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