From: Jon Harrop <jon@...>
Date: 2007-05-27T10:15:06+09:00
Subject: Re: Developing cross-platform web/GUI applications

M. Edward (Ed) Borasky wrote:
> Well, I wouldn't call Ruby a "functional" programming language in the
> same sense as Lisp/Scheme, Haskell and Erlang define themselves as
> functional programming languages.

Ok. I'm from an OCaml/F# background. May I just ask if anyone can translate
the following OCaml one-liner into Ruby:

  let rec nest ?(n=2) f x = if n=0 then x else nest ~n:(n-1) f (f x)

it nests "n" applications of "f" to "x" with "n" defaulting to 2 if it isn't
specified, e.g. "nest ~n:3 f x" gives f(f(f(x))).

This trivial example encapsulates much of what I love about OCaml and it
doesn't translate well into any other language that I know.

> Ruby is more an "object-oriented 
> programming language" in the same sense as Smalltalk and Java define
> themselves as object-oriented programming languages.

Hmm. I'm not an OO fan but I was under the impression that Ruby has much
better support for functions than Python.

>> 1. How widely is Ruby used on Linux, Mac OS X and Windows?
>>   
> It depends on what you mean by "widely used." It's installed by default
> on Macs,

Really? It is bundled by Apple? That's incredible! =8-)

>> 2. Are there compilers/interpreters targetting the JVM/.NET that make it
>> easy to develop GUI applications?
>>   
> Yes indeed! The JVM is supported by Sun's jRuby, Microsoft just
> announced a "Dynamic Language Run-time" that supports Ruby on .NET, and
> there are miscellaneous other implementations. I don't have any
> experience with the .NET versions, but I highly recommend jRuby.

Awesome!!! This is exactly the kind of thing I'm looking for.

>> 3. Has anyone done any significant work in this area using Ruby?
>>   
> If by "this area" you mean web applications, you pretty much have to
> have been living under a rock if you haven't heard about Ruby on Rails.
> ;).

Oh yeah, I forgot. :-)

I had a look at Ruby on Rails a while ago and, although I can do scientific
computing with my eyes closed, web programming is like double Dutch to me.
Couldn't make head nor tail of it. I think I'm improving now though. :-)

> But general GUI applications are a bit more obscure in Ruby. Most of 
> the major GUI toolkits have Ruby bindings, but there's no clear "first
> choice" among them.

Ok, thanks.

>> 4. Are scientists and engineers using Ruby?
>>   
> Yes, but it isn't as popular among them as Python is. I'm a
> scientist/engineer, and I use Ruby, along with Perl and R. But I've
> never taken the time to learn Python.

Are there many tools for scientists and engineers written in Ruby? What sort
of stuff do you write in Ruby?

Thanks very much!
-- 
Dr Jon D Harrop, Flying Frog Consultancy
The F#.NET Journal
http://www.ffconsultancy.com/products/fsharp_journal/?usenet