I am playing with Parsec and I want to combine two parsers into one with the result put in a pair, and then feed i开发者_C百科t another function to operate on the parse result to write something like
i read on Andrew Birkett’s blog Applicative arrows for XML &&& return to pure that we could mix arrows and applicative functors.
I was looking at the Applicative class within Haskell libraries and stumbled across Alternative. What is this class good for? A google search did not reveal anything particularly insightful. And it s
Applicatives compose, monads don\'t. What does the above state开发者_运维问答ment mean? And when is one preferable to other?If we compare the types
I have a type Image which is basically an c-array of floats. It is easy to create functions such as map :: (Float -> Float) -> Image -> Image, or zipWith :: (Float -> Float -> Float) -
I\'ve always found postfix languages like Fa开发者_JAVA百科ctor to be far more readable than prefix (Lispy languages) and infix/postfix languages (all C-style languages, if we include both operators a
In \"Learn You a开发者_如何学Python Haskell for Great Good!\" author claims that Applicative IO instance is implemented like this:
Whilst trying to better u开发者_运维问答nderstand Applicative, I looked at the definition of <*>, which tends to be defined as ap, which in turn is defined as:
I am using a small database pool in my web app. And this particular function: withPool pool = bracket (takeConn pool) (putConn pool)
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