On 05/08/2011 19:16, Kin-man Chung wrote:
> On 08/05/11 10:04, Mark Thomas wrote:
>> On 05/08/2011 17:48, Kin-man Chung wrote:
>>
>>> On 08/05/11 02:14, Mark Thomas wrote:
>>>
>>>> On 05/08/2011 00:12, Kin-man Chung wrote:
>>>>
>>>>
>>>>> One of the proposed features for this JSR is the inclusion of static
>>>>> fields in EL expressions. The Java syntax for static fields (e.g.
>>>>> "a.b.MyClass.field") is in direct conflict with the EL dot ('.')
>>>>> operator and using that syntax in EL would introduce an ambiguity at
>>>>> parse time. It has been suggested before that we keep the
>>>>> ambiguity at
>>>>> parse time, and use an ELResolver to resolve it run evaluation time.
>>>>>
>>>>> Instead of pursuing such idea, I'd like to use another idea from
>>>>> Spring
>>>>> EL, which uses the notation T() to denote a type. So to reference a
>>>>> static field one would write, for instance,
>>>>>
>>>>> #{"T(java.lang.System).out"}
>>>>>
>>>>> Spring EL also use T() to specify an instance of Class, but I think it
>>>>> overloads its meaning unnecessarily, when one can use T().class to do
>>>>> the same thing. But this is just an aside.
>>>>>
>>>>> I think this is a very good compromise. It is simpler to implement
>>>>> and
>>>>> should lead to better performance.
>>>>>
>>>>> Please tell me what you think, before I go and work out all the
>>>>> details
>>>>> in the spec. :-) Thanks.
>>>>>
>>>>>
>>>> My only concern would be if this introduced other ambiguities. I don't
>>>> see any so +1 from me.
>>>>
>>>>
>>>>
>>> The only ambiguity I see is the id "T", since T() can be taken to mean a
>>> function call. We may have to make T a reserved word. Hmm...
>>>
>> It is just another operator. I couldn't see a problem with that.
>>
>>
> Making T a reserved word prevents an user from doing things like
>
> elManager.defineFunction("", "T", myFunction);
> elProcessor.getValue("#{T()}); // ambiguity here!
>
> BTW, all operators that looks like an <id> are all reserved. Examples:
> "not", "and" etc. Making it reserved makes parsers easier.
Sorry, I meant I didn't see a problem with making it reserved.
Mark