[Haskell-cafe] IO help
miguelimo38 at yandex.ru
Thu May 7 05:56:53 EDT 2009
I have a suggestion.
Why don't you grab some introductory book on Haskell and learn Haskell syntax a little?
applebiz89 wrote on 07.05.2009 13:46:
> I havent done much IO at all in haskell, only within the function itself.
> However I want to get the input from the interface for the function and
> havent done this before.
> In my main function, I want to ask the user what they would like to do
> 'become fan' for example, then with their choice initiate the function and
> ask for the appropriate input for that function. This is the code below:
> main :: IO()
> do putStr "Hi there! what is your name: "
> fanName = getLine
> do putStr "1 = Insert film, 2 = Become a Fan, 3 = The number of fans of a
> film, 4 = Film released in a year: "
> input = getLine
> read input :: Int
What exactly do you think this line is going to do?
> (if input == 1 then main x = insertFilm  else if input == 2 then main x =
> becomeFan  else if input == 3 then main x = numberOfFans )
All these "main x =" are just syntax errors.
> Say they choose film in a given year function function:
> filmsInGivenYear :: Int -> [Film] -> [String]
> filmsInGivenYear filmYear films = [ title | (Film title director year fans)
> <- films, year == filmYear]
> I need to ask the user what filmYear they want to insert. But i need to do
> this from the main function...I chose to do an if statement to choose what
> function they want, but i dont know where to go from there?
> any help will be greatly appreciated.
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