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Update haskell.html.markdown
Minor improvements to polymorphic types
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@ -292,9 +292,9 @@ say Green = "You are Green!"
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data Maybe a = Nothing | Just a
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data Maybe a = Nothing | Just a
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-- These are all of type Maybe
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-- These are all of type Maybe
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Nothing
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Just "hello" -- of type `Maybe String`
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Just "hello"
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Just 1 -- of type `Maybe Int`
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Just 1
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Nothing -- of type `Maybe a` for any `a`
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----------------------------------------------------
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----------------------------------------------------
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-- 8. Haskell IO
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-- 8. Haskell IO
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@ -344,8 +344,8 @@ sayHello = do
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-- Let's understand better how the function `getLine` we just
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-- Let's understand better how the function `getLine` we just
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-- used works. Its type is:
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-- used works. Its type is:
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-- getLine :: IO String
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-- getLine :: IO String
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-- You can think of a value of type `IO String` as representing a
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-- You can think of a value of type `IO a` as representing a
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-- computer program that will generate a value of type `String`
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-- computer program that will generate a value of type `a`
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-- when executed (in addition to anything else it does). We can
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-- when executed (in addition to anything else it does). We can
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-- store and reuse this value using `<-`. We can also
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-- store and reuse this value using `<-`. We can also
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-- make our own action of type `IO String`:
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-- make our own action of type `IO String`:
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