Re: Who is afraid of arrows, was Re: [Haskell-cafe] ANNOUNCE: Haskell XML Toolbox Version 9.0.0

David Virebayre schrieb:

2010/10/12 Gregory Crosswhite :

...

Also, I don't see why one would prefer >>> over the standard function composition operator, ".".

With "." you have to read right-to-left to follow data's path.

For me that reading order isn't natural, and I imagine it is so for most people which don't have a mathematical background.

Combined with >>= / >> you have multiple reading direction in the same expression, as in

expression ( c . b . a ) `liftM` a1 >>= a2 >>= a3 reading order 6 5 4 1 2 3

http://www.haskell.org/haskellwiki/Direction_of_data_flow