Compiling Java 9

[Stephan Herrmann]

On 11/16/2016 11:19 PM, Jonathan Gibbons wrote:
>
>
> On 11/16/2016 02:08 PM, Stephan Herrmann wrote:
>> On 11/16/2016 10:02 PM, Alex Buckley wrote:
>>> - If you lex 'package', then the sequence must parse as the first alternative.
>>> - If you don't lex 'package', but rather lex 'import', then parsing is ambiguous until you've looked ahead to lex either 'open',
>>> 'module', or a keyword that can start TypeDeclaration. [Ignoring annotations for simplicity.]
>>> - If you lexed 'open' or module', then the sequence must parse as the second alternative; if you lexed anything else, then the
>>> sequence must parse as the first alternative.
>>
>> I just tried this:
>>
>> ---8<---
>> import open.module;
>>
>> module foo {
>> }
>> ---8<---
>>
>> According to lang-vm this should be legal. The import statement
>> contains restricted keywords in positions where they cannot be keywords.
>> => Parsing should succeed.
>> javac rejects this, which supports your explanation that lexical lookahead
>> should suffice to recognize a ModuleDeclaration.
>>
>> Which one will it be?
>>
>> Stephan
>>
>
> I suspect you're not using the latest javac.

9-ea-142 gives a syntax error:

module-info.java:3: error: class, interface, or enum expected

I'm downloading 9-ea-144 as we speak.

> Your example works for me, after I also create a class called open.module that I can
> import.

Thanks, so restricted keywords now follow the same rules throughout the file.
Sounds good.

And with your explanation (previous post) I'm confident that javac's implementation
and what I had in mind are congruent.

Still curious how a spec will faithfully capture this :)

Stephan