Re: Strings...immutable?

From:

Patricia Shanahan <pats@acm.org>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 21 Mar 2007 06:38:50 -0700

Message-ID:

<etrchb$jhu$1@ihnp4.ucsd.edu>

Wojtek wrote:

Patricia Shanahan wrote :

Bent C Dalager wrote:

In article <mn.a2197d73ca5e7b05.70216@a.com>, Wojtek <nowhere@a.com>
wrote:

...

I can set a reference to an object. I cannot set a reference to a
reference.

You can set a reference to a wrapped reference though. Why is the
difference significant?

I think it may be a reflection of the view that C pointers are the
ultimate definition of what a pointer should be.

C pointers can point to pointers, without them being wrapped in a struct
or array. Java references cannot point to other unwrapped Java
references, so Java pointers are not C pointers.

It goes along with the argument that Java references are not really
pointers because Java does not support pointer arithmetic.

Here's a question for people holding that view: Why should the
particular, and arguably peculiar, cluster of features that C associated
with pointers be the ultimate definition of pointerness?

I don't think that C has anything to do with the ultimate definition of
pointerness. You can setup the same thing in assembler (though you need
to manage it more). C just happens to have a convenient syntax which we
can use to illustrate points, er pointers, with (ducks...)

So, why should the features of assembly language address variables set
the requirements for something to be a pointer?

To me, that seems rather like saying Java does not have transfer of
control because it does not have an unrestricted goto.

Patricia