- Description of syntactic sugar
Summary of the various uses of syntactic sugar in Haskell
Functions
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- For more information, see the chapter 深入函數
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(+2)
(3-)
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\x -> x + 2
\x -> 3 - x
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Lists
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- For more information, see the chapters 列表和元組 and 深入列表
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| lists |
[1,2,3] |
1:2:3:[]
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| arithmetic sequences
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[1..5]
[1,3..9]
[1..]
[1,3..]
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enumFromTo 1 5
enumFromThenTo 1 3 9
enumFrom 1
enumFromThen 1 3
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| list comprehensions |
[ x | (x,y) <- foos, x < 2 ]
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let ok (x,y) = if x < 2 then [x] else []
in concatMap ok foos
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Records
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Do and proc notation
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- For more information, see the chapters 理解 Monad and Arrows
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| Sequencing
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do putStrLn "one"
putStrLn "two"
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putStrLn "one" >>
putStrLn "two"
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| Monadic binding
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do x <- getLine
putStrLn $ "You typed: " ++ x
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getLine >>= \x ->
putStrLn $ "You typed: " ++ x
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| Let binding
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do let f xs = xs ++ xs
putStrLn $ f "abc"
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let f xs = xs ++ xs
in putStrLn $ f "abc"
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Layout
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- For more information on layout, see the chapter on 縮進
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The 語法糖 module是這本維基書Haskell中的一個草稿。
你可以通過擴展它來幫助維基書。
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