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Comment by sshine | Hacker News Reader

> The <$> operator is just a synonym for the fmap function

This kind of "just" falls in the category of when mathematicians say "trivial" as in "deducible in few steps using the only applicable axioms", which mistakingly sounds like an arrogant "easy" to non-mathematicians.

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I think the author meant "just" as in: it is only another name. In Haskell, you can make an infix operator out of a function by putting it between backticks. Thus, `fmap` and <$> are synonyms. For example:

    (subtract 3) <$>    [1,2,3,4]  -- =[-2,-1,0,1]
    (subtract 3) `fmap` [1,2,3,4]  -- =[-2,-1,0,1]

My reading of that sentence is that “<$> might rightfully scare you but it is only a synonym for the fmap function.” Does that still sound arrogant?

As a mathematician this looks like standard usage of "just" in mathematics, but I do try to avoid doing that because it does sound arrogant and patronizing

yeah, the ignorant tend to misunderstand and incorrectly infer intent.

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