What is better done in Ruby and what is better done in Haskell? [closed]

Question

If you have experience with both Ruby and Haskell, which of the following best describes the applicability and comparative power of the two languages?

1. The two languages better suit different kinds of programs, i.e. Ruby is better for x and Haskell is better for y.
2. They are both general-purpose, and one language better for almost all applications than the other.
3. They are both general-purpose, and whether one language is better than the other is mostly just a matter of personal preference.

Or feel free to add your own conclusion. I know Ruby well, and have been studying Haskell for a few weeks without having written any serious applications with it. I primarily want to know which bits of my production Ruby applications I should try rewriting in Haskell, and also what future applications (not toy applications, but real production applications) I ought to consider writing in Haskell rather than Ruby.

Answer 1

which bits of my production Ruby applications I should try rewriting in Haskell?

What problems are you solving by rewriting your production Ruby application in Haskell? If you're just rewriting it for the sake of learning, then write everything you can in Haskell, the more you write the more you will learn. Haskell is a tool just like every other language, you shouldn't be deploying "real production applications" in Haskell unless you understand Haskell well enough to identify when it's the appropriate tool for the job.

Answer 2

In general, a Haskell program will run faster than an equivalent Ruby program, a fact which shouldn't be too surprising. If you need to do something where efficiency is important, Haskell would be better. On the other hand, writing the performance critical bits in something like C and calling that from either Haskell or Ruby would likely be faster still.

Both languages expect you to adopt their preferred paradigm to a significant extent, so really it's a matter of which approach you prefer.

That said, if you've only spent a few weeks with Haskell, I doubt you have enough feel for the language yet to decide whether you like it. If you really want to make the Right Choice (tm) I'd suggest spending a few months experimenting with Haskell and writing at least one non-toy application in it. After that, then decide.

Answer 3

The main difference is: Ruby is a "scripting language" and haskell is not.

The focus and strength of a scripting language is different.

Scripting languages are very good for rapid prototyping. Further, they are good for gluing together different components or library functions.

For instance, python has the the sage library. There is a list of libraries available within sage, see: http://www.sagemath.org/links-components.html With Python and Sage it is easy "glue" together the functionality of the libraries and write a program.

Scripting languages are also suitable for parts of a program that change often.

Libraries (often called system libraries) are better programmed in programming languages like Haskell. For instance, a fast web server implementation is better done in Haskell, e.g. haskell wrap, see: http://hackage.haskell.org/package/warp-0.3.2.3

There are further specific strengths of (pure) functional programming languages like haskell. Haskell is very suited for parallel programming.

Haskell + parallel:
http://stackoverflow.com/questions/8582580/why-is-concurrent-haskell-non-deterministic-while-parallel-haskell-primitives-p
http://stackoverflow.com/questions/3011668/how-difficult-is-haskell-multi-threading

Areas where haskell is a good option:
http://stackoverflow.com/questions/1604790/what-is-haskell-actually-useful-for/1605155#1605155

Answer 4

I feel qualified to answer this. I'm writing a database, Siege; I wrote the initial prototype in Ruby, but now it's entirely Haskell. Here are some conclusions I've drawn:

• Haskell is not just some academic toy, you can use it effectively for real world things,
• Haskell is more terse and expressive than Ruby,
• Haskell has methods of composition and abstraction that Ruby could only dream of,
• Haskell's type system is it's greatest asset,
• Being productive in Haskell is a lot of fun,
• For simple things Ruby requires less brain work to write,
• Ruby is a much better scripting language,
• Ruby's library support is far superior,
• Ruby is easier to learn and to become productive in,
• Ruby is more straight forward,