Examples of using Fmap in English and their translations into Vietnamese
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Colloquial
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Ecclesiastic
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Computer
Here's the general definition of fmap.
Here's how to rewrite this by using fmap.
So it's pretty much the same thing as fmap!
Actually, fmap can be defined only in terms of bind and return.
If we do fmap f(fmap g Nothing), we get Nothing,
xs should equal fmap f xs.
the implementation for fmap, we see that the law fmap id= id holds.
The outcome of fmap yields another context of the same type, which I can map R.
If we write that a bit more formally, it means that fmap id= id.
In other words, m>>= f is always the same thing as join(fmap f m)!
If we use fmap(replicate 3)
But we can't map a function that's inside a functor over another functor with what fmap offers us.
If we do fmap f(fmap g(Just x)),
The expression fmap(*2) is a function that takes a functor f over numbers
say, fmap and then bind it to a name in GHCI.
If we imagine what the type fmap would be if it only worked on our new pairs,
If we look at the implementation of fmap for, say, Maybe, we can figure
namely that pure f<*> x= fmap f x holds.
Anyway, it turns out that just like fmap,<*> can also be implemented by using only what the Monad type class give us.
Monad instance for something, you can give it a Functor instance just saying that fmap is liftM.