list literal gotcha and suggestion

[Reinier Zwitserloot]

We covered this; in other (popular) languages, {} refers to set  
literals and [] refers to list literals.

Either way you're going to confuse people.

  --Reinier Zwitserloot



On 2009/08/10, at 01:50, Paul Benedict wrote:

> Reinier,
>
>> Q: Should the syntax of initializing remain uniform in Java?
>> A: Obviously not; I dont think anybody is considering "new Foo[]  
>> { foo1,
>> foo2, foo3};" to be a decent syntax for a _list_ literal. I'm  
>> guessing
>> that's not what you meant, though. Rephrase the question?
>
> When I say "uniform initialization syntax", I mean curly braces would
> continue to indicate a series of literal values.
>
> int[] a = {1, 2, 3};
> List<Integer> b = {1, 2, 3};
> Set<Integer> c = {1, 2, 3};
> Map<Integer, String> d = {{1, "apple"}, {2, "orange"}, {3, "banana"}};
>
> As I opined before, I think one syntax is easy and naturally builds
> upon what is already laid down for array initialization. It to me is
> consistent with Java's syntactical "feel" -- while others have readily
> admitted PHP/Perl influence for the current proposal.
>
>> Q: Can operations be performed on the collection literal?  
>> 3.toString() is
>> illegal -- why would { 1, 2 }.toSet() ?
>> A: Unless you propose that "FooBar".toLowerCase(); is to be made  
>> illegal, I
>> don't really get your point here.
>
> I think "FooBar" is a poor example because String-literals can only be
> typed as Strings. If you can entertain that collection literals do not
> to have a type except by compiler conversion rules (as would be with a
> uniform initialization syntax), then refer to Neal's prior explanation
> on this matter. I think his explanation was adequate.
>
> Paul
>
> Paul