Re: Scoping and locating definitions

Hi Terry,

On 1/20/07, Terry Weissman <[e-mail]> wrote:
> The point is, in Python, if file A chooses to import package B, it is
> very unlikely to affect code operating in completely unrelated file
> C.  In Ruby, it's entirely possible that the import of B could have
> broken something that C depended on.

As you pointed out, this is a trade off between having a powerful
language and having a safe one.  Most languages that I know won't let
me redefine the + operator for integers.  I really like that Ruby lets
me do it.  (I haven't needed to redefine +, at least not yet.)

I can imagine a reasonable language that has the features you'd like.
I just wouldn't call it Ruby.

I'm glad Matz chose to position Ruby much more towards the "powerful"
end of the spectrum rather than the "safe" end.  There are domains
that can benefit from a lot of safety, and others that can benefit
from a lot of power.  If I were programming the control system for a
nuclear reactor, Ruby probably wouldn't be my first choice.  But
that's one reason I don't do those kinds of projects.

> If you are in a world where all the code is written by good,
> competent programmers who've agreed on the ground rules, Ruby can
> give them all a lot of power.  But if you're not so sure about your
> fellow programmers, or about code that you are loading off the net,
> then Ruby's model offers much less protection than Python's.
>
> This kind of thing would make me much more scared to work on a big
> project in Ruby than I would be in Python.

I wouldn't want to program a large project in Ruby with programmers
that I didn't trust.  But having been on projects like this using
"safer" languages, I also wouldn't want to program a large project in
_any_ language with programmers that I didn't trust.  There are just
so many ways another programmer can make a project difficult, and any
language can only protect you from a handful of them.

(Hi Jos!  How are you doing?)

Wayne

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Wayne Vucenic
No Bugs Software
Ruby, C#, and Erlang Agile Contract Programming in Silicon Valley