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An Interview With F# Creator Don Syme
OCatenac passes along an interview with Don Syme, chief designer of F#, which is Microsoft Research's offering for functional programming on the .Net platform. Like Scala, which we discussed last fall, F# aims at being an optimal blend of functional and object-oriented languages. "[Q] What is the best program you've seen written in F#? [A] I've mentioned the samples from F# for Scientists, which are very compelling... For commercial impact then the uses of F# in the finance industry have been very convincing, but probably nothing beats the uses of F# to implement statistical machine learning algorithms as part of the Bing advertisement delivery machinery. ... We've recently really focused on ensuring that programming in F# is simple and intuitive. For example, I greatly enjoyed working with a high-school student who learned F#. After a few days she was accurately modifying a solar system simulator, despite the fact she'd never programmed before. You really learn a lot by watching a student at that stage."
Last year I wanted to know what all the hoopla was about functional programming. I checked out Haskell, Scala, OCaML and F#. Coming from a Java/Delphi/C# background myself I had to go through it a couple of times before I "got" it. I'm glad I did because I banged out my first production IronPython lambda function on last Friday (yay!).
I know that MS bashing is popular here on Slashdot, but I really want to take a moment to say that the .NET Framework really is excellent. The ability to mix and match different paradigms and languages in a clean an concise manner which is a joy to program in.
Yeah I know patents bla bla mono bla bla Novell bla bla Miguel bla bla.
being Microsoft it will probably not run on 95% of our compute clusters
F# specifically supports Mono on Linux and OS X. I somehow doubt it's good enough for clusters, though...
In any case, I don't think that's the intended use case. It's not for computationally intensive stuff - you'd still want Fortran or C/C++ there, as you've rightly noted - but for the kind of computations that you do on your own box. These guys provide some supplement tools.
That said, it can still be used to massively parallelized, scalable tasks, since it has some stock parallelization primitives, and can also use .NET Parallel Framework (which is task/taskgroup-based automatic scheduler on lower level, and automatic parallelization of queries and transforms over sequences on higher level).
Therefore... Why should I care? What does F# do, for me as a scientist, that I should invest my time into it?
Do you, as a scientist, use Haskell or ML? If so, you can think of F# as the same kind of thing, but with first-class IDE and debugging support, and ability to quickly throw together UI frontends in WPF (it's pretty good for rather advanced visualization).
Functional-based programming languages are syntactically inferior to OO ones
Most likely just the ones that you've seen, and for the tasks you've thrown at them. I wouldn't write a line-of-business application in F#, sure, but I wouldn't write a parser in C# either.
While we're at syntax - I've yet to see any non-hybrid OO language which has anything matching the power and beauty of classic FP pattern-patching. For any sort of tree processing especially, it's a god send - whereas in OO you have to deal with ugly visitor pattern hack.
Then also, FP doesn't have to mean "alien syntax", either. Have you seen Scala? It has everything any self-respecting FP language needs to have, yet it's still very much OO-centric, and the syntax is broadly Javaesque.
To conclude... one of the first two OO languages, and the one to which pretty much all OO languages today owe at least half of their design, is Smalltalk. Coincidentally, it's also a very potent FP language - blocks are nothing but first-class functions, and they were used so pervasively in the language and the standard library that even the most basic conditional statement was actually a method call with two blocks...
And yet, Smalltalk is considered as one of the most pure OO languages ever.
Which is to say that OO and FP is really orthogonal, and not at all contradictive. You can have both, and either one is good for something different - so there's no reason not to have both, and get the best of both worlds.
I agree that Python has some strange things about it, but look at some sample f# syntax from Wikipedia:
let rec factorial n =
match n with
| 0I -> 1I
| _ -> n * factorial (n - 1I)
What do those funny characters mean? What's the I after the numbers? Compare to the python one liner:
def factorial(n): return 1 if n == 0 else n * factorial (n-1)
That makes sense even to someone with absolutely zero experience in the language.
Advanced??? Changed maybe. 30 years ago I taught myself BASIC from reference manuals in a few hours, enough to write a quadratic equation graphing program for my calculus class for extra credit. My second program was a password cracker so I could get higher priority on the university computer. I've modified code in languages that I had no experience in without any manual just by looking at syntax. So someone taking a few days to learn a programming language and modifying a planet simulator isn't all that impressive for a language ... they just found someone that learns quickly. I'm impressed in the person that picked it up, not the language. It mostly comes down to understanding if/then/else logic, loop constructs, and how to call methods after you learn syntax. Learning these constructs isn't too difficult, applying them takes a little more.
.. instead of spending a few days learning syntax, and a few months mastering a language, we now take a few days to learn syntax, and YEARS to learn all the calls and libraries that go along with it. My first attempt at C++ resulted in my giving up, not because I didn't understand the language but because I was trying to write GUI programs and didn't have the right book to explain which libraries to use and why.
So now
Programming tools have definitely advanced. The days of punched cards and line editors like EDLIN are far gone for most programming needs. It's nice that modern languages don't let you overflow arrays anymore or have to deal with pointers.
The biggest advances in programming??? Compilers, recursion, and object oriented syntax. I've seen far too many 'the next big thing' to get excited over something like this. Remember when C# was supposed to be the next big thing???
But I'm still using the same if/then/else and loop logic that I did 30 years ago. No matter how much things change, they still stay the same....
I rarely read replies, it's my opinion and if you thought about your opinion a little more, I'm OK with that.
So F# is for scientists and the finance industry, yet it cannot run on most mainframes (GNU/Linux or Unix), but there is mono that can, but does not work for computationally intensive applications.
That means that it will not be able to be used for Quantum Mechanical calculations or General Relativity calculations or any other calculation that scientists would like to perform. Nor would it scale to the large amount of real-time transactions that a bank or stock trading company would need to perform.
So how is F# better than Fortran & C/C++?