RFR - JDK-8202442 - String::unescape (Code Review)

[Jonathan Gibbons]

Jan,

Yes, thanks for clarifying my comment.

And to repeat, my comment was just to raise awareness in the different 
treatment according to JLS and to .unescape().

-- Jon


On 9/19/18 7:10 AM, Jan Lahoda wrote:
> I guess Jon's comment was that (per JLS) the outcome of unicode 
> unescapes can then participate in the escape sequences in String 
> literals. So, this:
> "\u005ct"
>
> is (as far as I know) a single character-literal (a tab), while it 
> seems that
> `\u005ct`.unescape()
>
> is two characters:
> \t
>
> Not sure if that's an intent or not.
>
> Jan
>
> On 18.9.2018 20:55, Jim Laskey wrote:
>> The intent, of course, is to offset the raw string literals 
>> non-translation of Unicode escapes and escape sequences. That is, 
>> have the multi-line cake and eat the escapes too.
>>
>> So a developer could have
>>
>>     String s = `
>>                     \t\tTitle
>>                     \t\t\tbody
>>            ...
>>
>>                     `.align().escape();
>>
>> to have tabs inserted in the string.
>>
>> "\\" "\u005c\u005c" and `\` all translate to the same string. 
>> `\u005c` translates to "\\u005c”. `\u005c`.unescape() thustranslates 
>> to be the same as "\\”, "\u005c\u005c" and `\`.
>>
>> Cheers,
>>
>> — Jim
>>
>>
>>
>>> On Sep 18, 2018, at 3:33 PM, Jonathan Gibbons 
>>> <jonathan.gibbons at oracle.com> wrote:
>>>
>>> Jim,
>>>
>>> In JLS, and hence javac, Unicode escape handling happens early on at 
>>> a low level, before string escape handling. This means that it is 
>>> technically possible to write string escape sequences in terms of 
>>> Unicode escapes.
>>>
>>> I'm not suggesting you should do the same here, but you should be 
>>> aware of the difference, compared to javac behavior.
>>>
>>> -- Jon
>>>
>>>
>>> On 9/18/18 10:51 AM, Jim Laskey wrote:
>>>> Please review the code for String::unescape. Used to translate 
>>>> escape sequences in a string, typically in a raw string literal, 
>>>> into characters represented by those escapes.
>>>>
>>>> webrev: http://cr.openjdk.java.net/~jlaskey/8202442/webrev/index.html
>>>> jbs: https://bugs.openjdk.java.net/browse/JDK-8202442
>>>> csr: https://bugs.openjdk.java.net/browse/JDK-8202443
>>>>
>>>> Cheers,
>>>>
>>>> — Jim
>>>>
>>>
>>