Expecting Integer.valueOf(String) to accept Literal format ...
ecki at zusammenkunft.net
Sat Apr 9 16:25:29 UTC 2016
actually Integer.decode is used to parse JLS Integers. And its JavaDoc
explicitely state that it does not support underscores. I would have
changed that method, not the valueOf.
I think there are some legit cases where changing the behavior of
valueOf can cause problems. It is (unfortunatelly) often used to verify
the format of a number (instead of retrieving its value). And if this
verificationsuddenly gets more lenient it might let numbers pass which
makes problems in other (possibly non-java) places.
Am Sat, 9 Apr
2016 21:22:01 +0600 schrieb "Tagir F. Valeev" <amaembo at gmail.com>:
> Strictly speaking there are many more ways to specify integer constant
> in Java. Like
> int x = 045;
> int x = 0x34;
> int x = 0b11101;
> So why should we support "4_5_6" only, but not "0x456"? Note that
> "045" is already parsed by Integer.valueOf, but as decimal number, not
> as octal. Thus I don't think that being valid syntax in Java language
> should be considered as a reason here.
> Also note that there are more integer parsing methods like
> Scanner.nextInt() and so on. I feel that they should provide
> consistent behavior with Integer.valueOf(). However changes in Scanner
> might break even more existing code.
> With best regards,
> Tagir Valeev.
> CON> I feel like this is an obvious API gap that should be fixed. If
> CON> it is a valid syntax in javac, it should be a valid syntax in
> CON> JDK APIs. My first impression was that this was an obvious
> CON> oversight.
> CON> - Charlie (mobile)
> CON> On Apr 9, 2016 21:04, "Christoph Engelbert" <me at noctarius.com>
> CON> wrote:
> >> Hey Andrew,
> >> Not sure it would risk breaking compatibility. It’s fairly easy to
> >> support it by just replacing underscore before parsing. Do you
> >> think of code that is expected to not parse underscore arguments?
> >> I think it’s a fair request to support underscore based integer
> >> representations, even though I never needed it yet, anyhow it
> >> makes sense to me to give users the possibility to have the same
> >> integer representation in, let’s say, properties files.
> >> Chris
> >> > On 09 Apr 2016, at 11:06, Andrew Haley <aph at redhat.com> wrote:
> >> >
> >> > On 08/04/16 23:36, kedar mhaswade wrote:
> >> >> As library writers however, how would you explain this mismatch?
> >> >
> >> > Changing valueOf(String) runs the risk of breaking existing Java
> >> > code, and Java takes compatibility very seriously. Whether it's
> >> > worth the risk is a matter of judgement.
> >> >
> >> > Andrew.
> >> >
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