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Re: immutable BigInteger

On 16/10/2007, at 2:47 PM, robert engels wrote:
I am not debating that immutable objects makes concurrent programming easier - it is just that immutable objects do not model real world (domain) objects very well.

If I have an instance of the car, and I paint it RED, I don't get a new instance of the Car,

The most efficient way to repaint the car would be: Color.GREEN.setRGB(255, 0, 0); You don't do this, for obvious reasons. :)

My point from the email you quoted, emphasis added: "As a general design rule, objects _that represent values_ should be immutable."

My other point would be that there are a lot more things that represent values (and that should be immutable until proven otherwise) that programmers don't think about. My employer has a standard coding test for new hires, and one bug that I'd say 90% of candidates introduce during the course of the test is related to modifying the contents of a collection when they should be creating a new collection. Most applicants find the bug when I say "you introduced a bug there, what is it?", but in the normal course of programming that wouldn't happen.

C


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 >Re: immutable BigInteger (From: robert engels <email@hidden>)
 >Re: immutable BigInteger (From: Charles Miller <email@hidden>)
 >Re: immutable BigInteger (From: robert engels <email@hidden>)



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