CODEWITHSUNDEEP
functionhaskell
markovuksanovic
markovuksanovic

Reputation: 15906

Haskell function definition and arguments list

I have the following function definitions (which are equivalent):

reverseWords :: String -> String
reverseWords wds = unwords . map reverse . words $ wds

and

reverseWords :: String -> String
reverseWords = unwords . map reverse . words

I understand that they are equivalent as they yield the same result but I'm a bit confused about the second form.

If I call a function like:

reverseWords abc

How does haskell decide where to place this 'abc' parameter?

Upvotes: 1

Views: 107

Answers (1)

Rizier123
Rizier123

Reputation: 59701

Haskell does not need to decide where to place abc. When you call reverseWords in your second example it will simply return unwords . map reverse . words.

And then abc gets applied to that with which you will end up with the same result as in your first example.

This is also called Point-free style as you can read more about it here: https://wiki.haskell.org/Point-free

Upvotes: 1

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