From: Dumaiu <Dymaio@...>
Date: 2007-12-10T02:19:00+09:00
Subject: Re: How much would variable declarations in Ruby make you wince?

On Dec 9, 11:00 am, Robert Klemme <shortcut...@googlemail.com> wrote:
> On 09.12.2007 16:11, Dumaiu wrote:
>
>
>
> > On Dec 8, 7:51 pm, "Just Another Victim of the Ambient Morality"
> > <ihates...@hotmail.com> wrote:
> >>     So, I had a conversation with a colleague of mine and he brought up a
> >> feature request for another language that is a lot like Ruby but is not
> >> Ruby.  It was an interesting request and, after I had thought about it a
> >> bit, I discovered that I would like this feature, too!
>
> > Hum.  Why don't you try comp.lang.ruby.like.but.not.ruby instead?  I
> > hear it's "phat."
>
> >>     The two most popular sources of bugs for me when programming in Ruby
> >> are:
>
> >> 1)  Passing the wrong object as a parameter to a method.
> >> 2)  Accidentally creating a new variable.
>
> > Seriously, as someone prone to lack of concentration, I agree.  A
> > great many programmers have concluded, probably from painful
> > experience, that typed variables reduce error.
>
> Item 2 above was about declared variables, not necessarily typed ones.

       Sorry, that was intended as a précis.  I probably should have
said 'typed and declared' so it would have applied to both.

>
> >  Also I think that
> > building error-testing into the code will scale better than reliance
> > only on unit testing.
> >    1). I'm not yet convinced that some kind of sophisticated DBC thing
> > amenable to duckies can't be created.
>
> IMHO DBC and duck typing do not mix very well because DBC takes away the
> flexibility which is one of the strengths.  Fact is, apparently there
> are people who are able to write complex applications in Ruby - even
> with more smart automatisms added.

	The paradigms are antipodal, hence the conflict.  But I *am not yet
convinced* that there is no acceptable middle ground between the
approach of trying to second-gues absolutely everything--which fights
the language--and the "you know it works because it works, that is,
doesn't blow up" approach.  Permit me to think further on this.

> >    2) would be helpful, but it may be a mistake to insist on a keyword.
> > I think we should concentrate on putting everything that can be into a
> > DUIIYDLI module ('Don't use it if you don't like it').  Then the
> > skeptics can't complain.
>
> That will we hard because you want the missing declaration be caught
> during parsing and compiling.  If you put this into a module then you
> probably need to go back to the source and reparse it which is not
> always possible.  I don't know how Perl does it but frankly, I do not
> really see Perl as the ideal example to model Ruby after.

	I don't need compile-time checking and would never ask to jam that
into the language.  I was more imagining something modular that would
mimic a lvar.  Don't care about Perl.

> Bottom line: if you want a safer language with typed and declared
> variables use one.

      Thanks, but I really like Ruby!

<snip>

> I also suggest to keep methods
> short.  This will help improve structure of the code and avoid all sorts
> of other bugs as well.

	Troo.  But then you gotta test 'em all, because it's no help if you
have a lot of little methods but don't know which one the bug is in.


     Sincerely,

         -Jonathan