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Direction of data flow

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In Haskell the direction of data flow symbolized by the notations differs amongst the notations. Both directions occur equally frequently:

from left to right:

function definition
 f x = x*x
(input left, output right)
 \ x -> x*x
do notation
 do f; g
monadic composition
 f >>= g
let expression
 let x = 2 in x*x
(first definition, then usage)

from right to left:

function application
 f x
 f $ x
(input right, applied function left)
 g . f
results of monads
 do x <- f
monadic composition
 g =<< f
where clause
 x*x where x = 2
(first usage, then definition)

1 Weblinks

2 See also

There is still something to translate from De/Flussrichtung