From: Dave Burt <dave@...>
Date: 2006-09-12T18:20:40+09:00
Subject: Re: Matrix

Michael Ulm wrote:
> Just Another Victim of the Ambient Morality wrote:
> 
>> "MonkeeSage" <MonkeeSage@gmail.com> wrote in message
>> n = 3
>> n = n + 1
>>
>>
>>     Matrices are no different and, so, you can do:
>>
>>
>> n = Matrix.scalar(2, 3)
>> n = n + Matrix.I(2)
>>
>>
>>     In both cases, the "number" types are immutable but the references
>> to them are not, as you say.  They both work exactly the same way. 
>> What are you trying to say?
>>
>>
> 
> I think he's trying to say, that there is no rational reason for
> leaving out the []= operator, and I agree.


The benefit is that you can assume no other code is modifying your matrix.

n = Matrix.I(2)
some_function(n)
p n # same as before

It's a good feature.

[]= would be useful, too, but I think to keep the immutability a better
addition that provides the same functionality could be provided; a
modified_at(x,y,value) method or something, but naming it is hard.

Cheers,
Dave