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Re: JLS 3/e -- Lots Of Errors

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On 02/04/2011 08:37 PM, Lawrence D'Oliveiro wrote:
> Here’s another fun one.
>
> In section 4.8, on page 58, it says:
>
>      The use of raw types is allowed only as a concession to compatibility of
>      legacy code. The use of raw types in code written after the introduction
>      of genericity into the Java programming language is strongly
>      discouraged. It is possible that future versions of the Java programming
>      language will disallow the use of raw types.
>
> (That last sentence is in bold.) However, in the discussion on page 136:
>
>      Note that expression names may be qualified by type names, but not by
>      types in general. A consequence is that it is not possible to access a
>      class variable through a parameterized type
>          class Foo<T>  {
>          public static int classVar = 42;
>          }
>          Foo<String>.classVar = 91; // illegal
>      Instead, one writes
>          Foo.classVar = 91;
>      This does not restrict the language in any meaningful way. Type
>      parameters may not be used in the types of static variables, and so the
>      actual parameters of a parameterized type can never influence the type
>      of a static variable. Therefore, no expressive power is lost.
>      Technically, the type name Foo above is a raw type, but this use of raw
>      types is harmless, and does not give rise to warnings.
>
> So one the one hand raw types are deprecated, but on the other hand they are
> the only permitted way to access static fields of a parameterized type.

That is neither an error nor a typo, nor sloppy, but a precise description of 
the actual rules.

You may think the rules are screwy, but the JLS itself is not sloppy nor 
erroneous there.

-- 
Lew
Ceci n'est pas une fenêtre.
.___________.
|###] | [###|
|##/  | *\##|
|#/ * |   \#|
|#----|----#|
||    |  * ||
|o *  |    o|
|_____|_____|
|===========|

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Re: JLS 3/e -- Lots Of Errors Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-02-05 14:37 +1300
  Re: JLS 3/e -- Lots Of Errors Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-05 00:15 -0500
    Re: JLS 3/e -- Lots Of Errors Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-02-05 10:10 -0500
    Re: JLS 3/e -- Lots Of Errors Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-02-05 19:41 +1300
  Re: JLS 3/e -- Lots Of Errors Lew <noone@lewscanon.com> - 2011-02-04 23:59 -0500
    Re: JLS 3/e -- Lots Of Errors Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-02-05 19:42 +1300
      Re: JLS 3/e -- Lots Of Errors Lew <noone@lewscanon.com> - 2011-02-05 09:34 -0500
        Re: JLS 3/e -- Lots Of Errors "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2011-02-05 12:52 -0500

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