[Haskell-cafe] Monad Description For Imperative Programmer
wagner.andrew at gmail.com
Wed Aug 1 09:27:43 EDT 2007
> say you have this code :
> putStrLn "1" >> putStrLn "2" >> putStrLn "3"
> you can imagine each of the calls to putStrLn gets implicitly passed a
> variable (here, the world ) and they happen in succession so it's
> "like a loop".
It breaks down further as soon as you add any amount of complexity to
the code as well. E.g.:
putStrLn "1" >> getLine >>= \line -> putStrLn line >> putStrLn "end"
This prints something, gets something from the user and prints it, and
then prints something else. The equivalent imperative pseudo-code is
line = inputLine();
Not loop-ish at all!
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