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| == A Tour of the Haskell Prelude ==
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| ;<span id="abs">'''abs'''</span>:
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| {| border="0" cellpadding="4"
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| |-
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| | ''type:'' || <hask>abs :: Num a => a -> a</hask>
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| |-
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| | ''description:'' || returns the absolute value of a number.
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| |-
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| | ''definition:''
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| | <haskell>
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| abs x
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| | x >= 0 = x
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| | otherwise = -x
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| </haskell>
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| |-
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| | ''usage:''
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| | <pre>
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| Prelude> abs (-3)
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| 3
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| </pre>
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| |}
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|
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| ;<span id="all">'''all'''</span>:
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| {| border="0" cellpadding="4"
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| |-
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| | ''type:'' || <hask>all :: (a -> Bool) -> [a] -> Bool</hask>
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| |-
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| | ''description:'' || Applied to a predicate and a list, returns True if all elements of the list satisfy the predicate, and False otherwise. Similar to the function [[#any]].
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| |-
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| | ''definition:''
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| | <haskell>
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| all p xs = and (map p xs)
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| </haskell>
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| |-
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| | ''usage:''
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| | <pre>
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| Prelude> all (<11) [1..10]
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| True
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| Prelude> all isDigit "123abc"
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| False
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| </pre>
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| |}
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