PreludeTour: Difference between revisions
No edit summary |
No edit summary |
||
Line 23: | Line 23: | ||
|} | |} | ||
;'''all''': | ;<span id="all">'''all'''</span>: | ||
{| border="0" cellpadding="4" | {| border="0" cellpadding="4" | ||
|- | |- | ||
| ''type:'' || <hask>all :: (a -> Bool) -> [a] -> Bool</hask> | | ''type:'' || <hask>all :: (a -> Bool) -> [a] -> Bool</hask> | ||
|- | |- | ||
| ''description:'' || | | ''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]]. | ||
|- | |- | ||
| ''definition:'' | | ''definition:'' |
Revision as of 13:37, 26 October 2009
A Tour of the Haskell Prelude
- abs
type: | abs :: Num a => a -> a
|
description: | returns the absolute value of a number. |
definition: | abs x
| x >= 0 = x
| otherwise = -x |
usage: | Prelude> abs (-3) 3 |
- all
type: | all :: (a -> Bool) -> [a] -> Bool
|
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. |
definition: | all p xs = and (map p xs) |
usage: | Prelude> all (<11) [1..10] True Prelude> all isDigit "123abc" False |