From: "framefritti@..." <framefritti@...>
Date: 2008-04-16T02:25:03+09:00
Subject: Re: Ada vs Ruby

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...]

Maybe your initial productivity (mesured in lines of code written for
unit of time) can be smaller because of the loss of flexibility,
but if your software is very large you gain in debugging and
maintenace
time.

Of course, if you  just want to extract data from a CSV file, or write
a wget-like program, Ada can be a "gun for mosquitos."