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From James Carman <ja...@carmanconsulting.com>
Subject Re: [lang 3] static or dynamic type checks?
Date Fri, 27 Nov 2009 01:38:51 GMT
Yes, but if the check passes, there's no need to create the Object[]
for single-argument method invocations.

On Thu, Nov 26, 2009 at 10:59 AM, Paul Benedict <pbenedict@apache.org> wrote:
> The purpose of var-args, at least from my vantage, is to produce
> detail messages that are used by java.lang.String.format.
>
> Paul
>
> On Thu, Nov 26, 2009 at 7:11 AM, James Carman
> <james@carmanconsulting.com> wrote:
>> I just wrote a class that included...
>>
>>    public static <T> T someMethod(T val)
>>    {
>>        System.out.println("Single value method!");
>>        return val;
>>    }
>>
>>    public static <T> T[] someMethod(T... values)
>>    {
>>        System.out.println("Multi-value method.");
>>        return values;
>>    }
>>
>>    public static void main(String[] args)
>>    {
>>        someMethod("Hello");
>>        someMethod("Hello", "World");
>>    }
>>
>> When I ran it, it printed:
>>
>> Single value method!
>> Multi-value method.
>>
>> So, what's the big deal?  Create a single-value method and create a
>> multi-value method.  I must be missing something in this discussion.
>>
>> On Thu, Nov 26, 2009 at 12:16 AM, Paul Benedict <pbenedict@apache.org> wrote:
>>> If we want to implement LANG-508 (Validate: add message parameter
>>> construction via elllipsis notation to speed up processing), I am
>>> really concerned with the many overloaded versions of #validIndex()
>>> and #notEmpty() that solely differ by static argument type:
>>> Collection, Object, Object[], CharSequence, etc.
>>>
>>> Because var-args instantiate a new Object[], it won't be possible to
>>> easily create one-argument optimized overloaded versions to prevent
>>> the creation. Such as:
>>> public static <T> T[] notEmpty(Object array, String message, Object var1);
>>> public static <T> T[] notEmpty(Object array, String message, Object
>>> var1, Object var2);
>>> public static <T> T[] notEmpty(Object array, String message, Object
>>> var1, Object var2, Object var3);
>>> public static <T> T[] notEmpty(Object array, String message, Object
>>> var1, Object var2, Object var3, Object... vars);
>>>
>>> I am following the good advice on Joshua Bloch on this one. It's item
>>> #42 in his Effective Java book.
>>>
>>> I want to eliminate the overloaded versions by type and check those
>>> types using instanceof instead. Thoughts?
>>>
>>> Paul
>>>
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>>>
>>>
>>
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>>
>
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>

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