From: Dave Thomas <Dave@...>
Date: 2002-11-28T02:14:07+09:00
Subject: Re: Things That Newcomers to Ruby Should Know (11/24/02)

William Djaja Tjokroaminata <billtj@y.glue.umd.edu> writes:

> I don't think the concept of mutability is ever mentioned in the pickaxe
> book.  In "Python Essential Reference", for example, the concept of
> mutability is introduced early, and it seems that in Python (at least in
> version 1.5.2) only lists (arrays) and dictionaries (hashes) are mutable.

I'd be surprised if File was immutable :)

> I think it will suffice for all of us if Matz simply gives the
> formal list of which objects/classes are mutable and immutable.  I
> agree with you that the implementation is secondary.

I don't see why we need to waste Matz's time producing this list. It's
clear which methods change an object's state.

My point was that you were giving the impression that the lack of ++
for Fixnum was an implementation issue, and that alternative Ruby
implementations might support it. Given that you produce a document
aimed at newcomers, it was important to me that this misunderstanding
was cleared up.


Cheers


Dave