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Comment by ijt | Hacker News Reader

I was surprised that the author thinks the syntax of Haskell is no better than that of C++. Let's look at a typical example. In Haskell, the signature for sort is

sort :: Ord a => [a] -> [a]

which just says that it takes a list of comparable things and returns another list of the same type. Here's the type signature for sort in C++:

template <class RandomAccessIterator, class Compare> void sort ( RandomAccessIterator first, RandomAccessIterator last, Compare comp );

The difference in terseness and clarity is a big reason why I use Haskell when I have a choice.

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Please. The difference in terseness and clarity is made up almost entirely of the lenths of the symbol names:

template<class I, class C> void sort(I a, I b, C cmp);

Now, the concepts aren't 1:1; Haskell for obvious reasons doesn't represent the idea of operating on storage directly, so you can't have an iterator and need to return a "new" list. C++ makes you write out the types you are parametrizing instead of getting it implicitly. And there are no doubt some really good arguments why Haskell is terser and clearer than C++.

But this isn't one of them. Come on.

The difference is not only due to identifier length. Haskell's sort is a function in the mathematical sense. By looking at its type, I can see the input and output at a glance and understand how to use it. It's not immediately obvious from the signature of the C++ sort procedure that the "first" and "last" arguments are being used for both input and output. When you abbreviate the identifiers for STL sort it's even less obvious what's going on.

There's nothing "immediately obvious" to that Haskell signature at all. You need to understand the [] syntax for list typing. You need to understand that the language defintion has a built-in notion of "list". You need to understand the idea of functions having types themselves (a huge hurdle if you're new to functional languages). And you need to understand that weird "Ord" decorator gadget and that it means the types can be compared. Basically, you can't understand that line noise at all unless you know Haskell. Duh.

Likewise, if you're truly confused about C++ STL iterators you're just waving your own ignorance around. They're a simple concept pervasively applied in the library. No experienced programmer is going to be confused by that function declaration.

Look, very good cases can be made for functional languages. But this is just surface-level stuff that frankly isn't going to help anyone. Expressing a sort simply isn't a complicated thing in C++ or Haskell and trying to claim otherwise is just dumb.

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