| Portability | portable |
|---|---|
| Stability | in-progress |
| Maintainer | http://community.haskell.org/~ndm/safe |
Safe
Description
A library for safe functions, based on standard functions that may crash. For more details see http://community.haskell.org/~ndm/safe/
In general, each unsafe function has up to 4 forms.
Since tail has all the possible forms, it is fully documented.
The others all follow the same pattern.
-
Note, takes an extra argument which supplements the error message,tailNote -
Def, take an extra argument to give when a crash would otherwise happen,tailDef -
May, wraps the result in a Maybe,tailMay -
Safe, returns a default type if possible,tailSafe
This library also introduces three brand new functions:
-
at- synonym for(!!) -
lookupJust- defined aslookupJust k = fromJust . lookup k -
abort- same aserror, but different intended meaning
- tailDef :: [a] -> [a] -> [a]
- tailMay :: [a] -> Maybe [a]
- tailNote :: String -> [a] -> [a]
- tailSafe :: [a] -> [a]
- initDef :: [a] -> [a] -> [a]
- initMay :: [a] -> Maybe [a]
- initNote :: String -> [a] -> [a]
- initSafe :: [a] -> [a]
- headDef :: a -> [a] -> a
- headMay :: [a] -> Maybe a
- headNote :: String -> [a] -> a
- lastDef :: a -> [a] -> a
- lastMay :: [a] -> Maybe a
- lastNote :: String -> [a] -> a
- minimumDef :: Ord a => a -> [a] -> a
- minimumMay :: Ord a => [a] -> Maybe a
- minimumNote :: Ord a => String -> [a] -> a
- maximumDef :: Ord a => a -> [a] -> a
- maximumMay :: Ord a => [a] -> Maybe a
- maximumNote :: Ord a => String -> [a] -> a
- foldr1Def :: a -> (a -> a -> a) -> [a] -> a
- foldr1May :: (a -> a -> a) -> [a] -> Maybe a
- foldr1Note :: String -> (a -> a -> a) -> [a] -> a
- foldl1Def :: a -> (a -> a -> a) -> [a] -> a
- foldl1May :: (a -> a -> a) -> [a] -> Maybe a
- foldl1Note :: String -> (a -> a -> a) -> [a] -> a
- fromJustDef :: a -> Maybe a -> a
- fromJustNote :: String -> Maybe a -> a
- assertNote :: String -> Bool -> a -> a
- at :: [a] -> Int -> a
- atDef :: a -> [a] -> Int -> a
- atMay :: [a] -> Int -> Maybe a
- atNote :: String -> [a] -> Int -> a
- readDef :: Read a => a -> String -> a
- readMay :: Read a => String -> Maybe a
- readNote :: Read a => String -> String -> a
- lookupJust :: Eq a => a -> [(a, b)] -> b
- lookupJustDef :: Eq a => b -> a -> [(a, b)] -> b
- lookupJustNote :: Eq a => String -> a -> [(a, b)] -> b
- abort :: String -> a
Documentation
tailNote :: String -> [a] -> [a]Source
tail "help me" [] = error "Pattern match failure, tail [], help me" tail "help me" [1,3,4] = [3,4]
minimumDef :: Ord a => a -> [a] -> aSource
minimumMay :: Ord a => [a] -> Maybe aSource
minimumNote :: Ord a => String -> [a] -> aSource
maximumDef :: Ord a => a -> [a] -> aSource
maximumMay :: Ord a => [a] -> Maybe aSource
maximumNote :: Ord a => String -> [a] -> aSource
foldr1Note :: String -> (a -> a -> a) -> [a] -> aSource
foldl1Note :: String -> (a -> a -> a) -> [a] -> aSource
fromJustDef :: a -> Maybe a -> aSource
See fromMaybe
fromJustNote :: String -> Maybe a -> aSource
assertNote :: String -> Bool -> a -> aSource
lookupJust :: Eq a => a -> [(a, b)] -> bSource
lookupJust key = fromJust . lookup key
lookupJustDef :: Eq a => b -> a -> [(a, b)] -> bSource
lookupJustNote :: Eq a => String -> a -> [(a, b)] -> bSource