[Haskell-cafe] Re: [Haskell] Re: Help : A problem with IO

wman 666wman at gmail.com
Mon Dec 15 05:35:24 EST 2008


you probably got it pointed out in haskell-beginners, but in case not:

On Thu, Nov 27, 2008 at 7:10 PM, abdullah abdul Khadir <
abdullah.ak2002 at gmail.com> wrote:

> a) I need to put a do after else for more than one instruction (?)


No, the do thingy is a syntactic sugar for chaining "warm, fuzzy" (the
"preffered" wannabe-joke-term for the presumably scary term monads/monadic)
operations.

it allows you to write in "classical" imperative/sequential style instead of
chaining operations manually (using the >> and >>= operators, which the do
notation translates into anyway). lookup some monad tutorials/docs.

you are right in that if there is only one operation, no transformation is
needed, so the do is unnecessary.
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