From: Todd Benson <caduceass@...>
Date: 2008-04-16T02:46:22+09:00
Subject: Re: Ada vs Ruby

On Tue, Apr 15, 2008 at 12:25 PM, framefritti@gmail.com
<framefritti@gmail.com> wrote:
> Interesting thread... also because I use both Ruby and Ada.  No,
>  better...
>  since I _love_ both Ruby and Ada.  Yes, they could not be more
>  different and...
>  no, I do not have any split-personality problem (at least, non that I
>  am
>  aware of it...:-)
>
>  In my personal experience, they are both great languages and each one
>  "shines"
>  in its field.  I use Ruby for small to medium-large applications where
>  "duck
>  typing" allows you to write good and flexible software in little
>  time.  However,
>  I discovered that when I go to large to very large applications, a
>  pedantic language
>  as Ada (which would not allow you to write sqrt(5) because "5" is an
>  integer and
>  not a float... my first Ada program...) is a better choice since many
>  errors
>  are caught at compile time and many others just at the first few runs
>  by the
>  checks automatically inserted by the compiler.  For example, if you
>  write
>
>    type Month_Day is new Integer range 1..31;
>
>    MD : Month_Day := 30;
>
>    MD := MD + 3;
>
>  you will get a runtime error because MD exit from the allowed range.
>  In C this bug could comfortably sleeps for centuries...
>
>  Moreover, if you define
>
>   type Counter is new Integer;
>
>  Ada strong typing will prevent you to assign a value of type Month_Day
>  to
>  a variable of type Counter (the magic word is "new") and this makes a
>  lot
>  of sense, unless in your application you can convert a day into a
>  counter.
>  I discovered that  when your software grows larger, this kind of
>  constraints
>  that you _ask to the compiler_ to enforce on you, can really help.
>  [there
>  are *lots* of discussion about the usefulness of the introduction of
>  new incompatible types.  The sentece above is just my opinion,
>  based on some personal experience. I hope I did not open a new
>  can of worms...]

You can "type" your variables in Ruby if you have to.  I don't think
that's the problem.  It's the possibly reckless meta-programming in
libraries you use (I'm not talking about you, Trans, I think Facets is
great).

Being an engineer and a db guy, you would think that Ruby is the most
god awful thing I've ever seen.  Well, it has its place.

For realtime, Michael is right about the "time of execution" being
_the_ important thing.  I would like to see in the future, however, a
Ruby that talks to the hardware like RTLinux or QNX.  I'd take up such
a project myself, except I don't know enough C or assembly.  I suppose
you'd have to make certain objects allowed to have free reign over the
processor/memory.  Like an Object#become_real, though that's a little
scary :)

Todd