View source for Direction of data flow

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

from right to left:
{|
| function application   || <hask> f x </hask>, <hask> f $ x </hask> || (input right, applied function left)
|-
| composition            || <hask> g . f </hask>
|-
| results of monads      || <hask> do x <- f </hask>
|-
| monadic composition    || <hask> g =<< f </hask>
|-
| where clause           || <hask> x*x where x = 2 </hask> || (first usage, then definition)
|}


== Weblinks ==

* http://www.haskell.org/pipermail/libraries/2005-August/004315.html
* http://www.iba-cg.de/doc/hal1-haskell-with-style.pdf

== See also ==

There is still something to translate from [[De/Flussrichtung]]

[[Category:Syntax]]