[bad_user]

I think the article is spammy and has a clickbait title. Unfortunately reading and addressing the actual article on Hacker News is old-fashioned.

StackOverflow surveys, while interesting, are probably meaningless because they suffer from selection bias. Even so, I would guess that F# developers are very well paid, like other developers of FP languages, but it's probably not because they work with F#. The causality is likely reversed - good developers that tend to be well paid are also the kind of people naturally interested in expanding their skill set, hence interested in FP languages.

Nothing screams spam more than usage of a hot keyword like "functional programming" while leaving hints that you don't understand what you're talking about. I would expect an article that reads like a marketing brochure to at least make a short attempt at explaining what functional programming is. If you copy/paste testimonials from fsharp.org/testimonials, you could also copy/paste from Wikipedia. But then, their own course named "Functional Programming" doesn't seem to have anything to do with actual functional programming: https://fsharp.tv/courses/functional-programming/

[insulanian]

> their own course named "Functional Programming" doesn't seem to have anything to do with actual functional programming

Why do you think so?

[jackmott]

F# was also voted most LOVED language in the F# survey.

[smoothdeveloper]

In the Stack Overflow survey :)

[ZenoArrow]

Functional programming is a broad term that at its core describes languages that allow you to pass functions around as values to other functions.

In other words, when using a function the parameters of that function can be defined as other functions instead of needing to be precalculated variables or constants.

That's basically all that links functional programming languages, all other language design decisions can vary.

[louthy]

Most OO languages can do this now, and they wouldn't be classed as functional languages. I know this is always a sticky subject, but for me I prefer to think of functional languages as 'expression oriented' rather than 'statement oriented'.

[sremani]

F# is a functional first language, yes, C# with Func<> can do many things, but functional code in F# is just smooth and easy, unlike C#, where you have to put up with lot of noise.

[louthy]

I haven't mentioned or was making any points about F# or C#; I was commenting on what appears to be your definition of a functional language, that is "Functional programming is a broad term that at its core describes languages that allow you to pass functions around as values to other functions".

Even if that meant something in the past, it really isn't a useful definition any more, because pretty much all languages do this. That's why I offered my alternative description. Even if it too has flaws, I think it's a more meaningful description.

[ZenoArrow]

> "I haven't mentioned or was making any points about F# or C#; I was commenting on what appears to be your definition of a functional language"

sremani != ZenoArrow (though if you read this sremani, thank you for attempting to clarify).

There are many 'multi-paradigm' languages, and C# is one of them. From the C# Wikipedia page...

https://en.wikipedia.org/wiki/C_Sharp_(programming_language)

"C# (pronounced as see sharp) is a multi-paradigm programming language encompassing strong typing, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines."

What makes a language 'functional' is first-class functions (i.e. functions that can be treated as values, which is what I was referring to in my earlier post).

As sremani said, F# is 'functional first', in the sense that the language is designed to make functional algorithms straightforward to express. You can write C# in a functional way too, but there's less syntactic sugar for this style of programming.

Hope that clears it up.

[louthy]

> sremani != ZenoArrow

Apologies, my mistake.

> Hope that clears it up.

First paragraph on the Wikipedia page for Functional Programming [1]:

"In computer science, functional programming is a programming paradigm—a style of building the structure and elements of computer programs—that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data. It is a declarative programming paradigm, which means programming is done with expressions[1] or declarations[2] instead of statements."

I'll stick with my definition.

Hope that clears it up.

[1] https://en.wikipedia.org/wiki/Functional_programming

[markfsharp]

Pure functions, i.e. that are 1) idempotent 2) have all their arguments passed in 3) cause no side effects as a by product of evaluating the function are fundamental to functional programming.

[louthy]

But not fundamental to the definition of a functional language. F# isn't pure, but most would call it a functional language - so purity is surely not 'fundamental' - in fact most functional languages aren't pure.

That's why I prefer to stick to the 'expression oriented' concept, it seems to be the thing that captures most, if not all, functional languages. But I guess just like there are plenty of people that wouldn't call Java OO (and would prefer the Alan Kay definition), there are plenty that will disagree with any definition of 'functional'

(preparing for the inevitable 'functional first' comment).

[vram22]

Are there any terms/concepts in math/CS that are related to or similar to "idempotence"?

[vram22]

I'm not an expert on this subject (have only dabbled in a few FP languages over the years), but what I've read in various sources leads me to think that the term "functional programming" itself is not very well-defined, or, to put it another way, different people may have different definitions of it, each including and excluding various language features or capabilities. Is that right? Any experts care to comment?

[chc]

Yes, but you could say the same about "object-oriented programming" (is it about inheritance? message passing? N/A?) and even something as well-defined as "pass by reference" (many people apply this term to Java, many others think that is completely wrong).

Ultimately, we have to live in a world where words are kind of ambiguous, but I think we should try to avoid useless definitions. The definition where "a functional programming language is one that can pass functions around" is extremely useless, because it applies to every modern programming language including C and C++. Whatever you want the term to mean, it shouldn't be that, because that distinguishes nothing.

[ZenoArrow]

> "Whatever you want the term to mean, it shouldn't be that, because that distinguishes nothing."

It's not extremely useless when you consider most programming languages cover multiple PL paradigms.

Functional languages are a spectrum. On one end you have pure functional languages like Haskell where you're forced to use functional algorithms for all computation, but there are languages in the middle of that spectrum like C# which support a bunch of functional language constructs (take a look here for a selection: http://www.codeaddiction.net/articles/13/lambda-expressions-... ) even if they aren't purely functional.

My argument is, any definition of functional programming that ignores the mid part of the spectrum is useless, as it ignores that most languages do not strictly follow a single approach like Haskell but allow you to adapt to different styles (i.e. most programming languages are multi-paradigm). Even F# and Ocaml allow you to write in an imperative style if you so choose, and many people would class them as 'functional' languages.

[tome]

> functional languages like Haskell where you're forced to use functional algorithms for all computation

No you're not. Haskell supports mutable, imperative, algorithms just fine.

https://hackage.haskell.org/package/base-4.9.0.0/docs/Data-I...

https://hackage.haskell.org/package/base-4.9.0.0/docs/Contro...

https://hackage.haskell.org/package/stm-2.4.4.1/docs/Control...

[vram22]

Agreed.

[smoothdeveloper]

I think the title can be alleged mostly to the misconception which is prevalent at Microsoft since F# was introduced as a commercial product (before it used to be a Microsoft Research product).

Maybe you are unaware of that?

F# is a pretty good general purpose programming language and that is what the title and article tries to promote (albeit it doesn't give enough and diversified examples).

F# is also a reasonably easy programming language which puts emphasis first on "functional programming" (which you frame as hot keyword, I doubt the language was made to fill a hot keyword).

I don't know about the for pay contents of fsharp.tv, but I gather they might be introductory and try to bring understanding of "functional programming" aspects to an audience which isn't versed in it, it is sure good for them if "functional programming" is a hot keyword and people are looking for training material to pickup that language, but I wouldn't dismiss that as being spammy.

Chill out dude :)