Double-semicolon in import statements

[Jonathan Gibbons]

True,

FWIW, if we change javac such that the set of programs accepted by javac 
is changed, we have an process (currently Oracle internal) to get 
approval for such a change.   So, we would not simply change javac on a 
whim to meet the spec; we would at least have other eyes looking at the 
behavioral change to determine if it is "acceptable".

-- Jon


On 08/02/2013 02:00 PM, John Spicer wrote:
>
> On Aug 2, 2013, at 4:45 PM, Jonathan Gibbons 
> <jonathan.gibbons at oracle.com <mailto:jonathan.gibbons at oracle.com>> wrote:
>
>> In general, it is better/simpler to change javac to conform to the 
>> spec. (Except when it is not.)
>
> Well, you sure can't argue with that statement  :-)
>
> It is unfortunate that, in the example given, if the user swaps what 
> look like import declarations with a redundant semicolon the code 
> changes from being invalid to valid (or vice-versa if the code began 
> in the other sequence).
>
> John.
>
>>
>> -- Jon
>>
>> On 08/02/2013 11:36 AM, Jeremy Manson wrote:
>>> Just out of my own curiosity, who decides whether to change the spec 
>>> or javac?
>>>
>>> Jeremy
>>>
>>>
>>> On Fri, Aug 2, 2013 at 10:25 AM, John Spicer <jhs at edg.com 
>>> <mailto:jhs at edg.com>> wrote:
>>>
>>>
>>>     On Aug 2, 2013, at 12:57 PM, Alex Buckley
>>>     <alex.buckley at oracle.com <mailto:alex.buckley at oracle.com>> wrote:
>>>
>>>     > Nope, the production is:
>>>     >
>>>     > CompilationUnit:
>>>     >  PackageDeclarationopt ImportDeclarationsopt TypeDeclarationsopt
>>>     >
>>>     > So that's a javac bug. (And a reason for minimizing undue
>>>     flexibility in the language in the first place.)
>>>
>>>     I'm generally happier to ban things like extra semicolons, but
>>>     it seems to me that "import x.y;;" should be allowed regardless
>>>     of what follows.
>>>
>>>     FWIW, out front end does give the appropriate error, the rules
>>>     just seem odd to me.
>>>
>>>     John.
>>>
>>>     >
>>>     > Alex
>>>     >
>>>     > On 8/1/2013 12:59 PM, Jeremy Manson wrote:
>>>     >> Alex,
>>>     >>
>>>     >> What about the following, which also compiles?  Can you
>>>     >> have ImportDeclaration TypeDeclaration ImportDeclaration?
>>>     >>
>>>     >> import java.util.HashMap;;
>>>     >> import java.util.LinkedList;
>>>     >>
>>>     >> public class Semicolon {
>>>     >>   public static void main(String[] args) {
>>>     >>      System.out.println("This program should not compile");
>>>     >>   }
>>>     >> }
>>>     >>
>>>
>>>
>>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.openjdk.java.net/pipermail/compiler-dev/attachments/20130802/9a7122fc/attachment.html