Hoogle Search

Within Stackage Nightly 2025-10-09 (ghc-9.12.2)

Note that Stackage only displays results for the latest LTS and Nightly snapshot. Learn more.

Exact lookup

1. fromSet :: (k -> a) -> Set k -> Map k a

   containers	Data.Map.Strict.Internal

   Build a map from a set of keys and a function which for each key computes its value.

   fromSet (\k -> replicate k 'a') (Data.Set.fromList [3, 5]) == fromList [(5,"aaaaa"), (3,"aaa")]
   fromSet undefined Data.Set.empty == empty
   

2. keysSet :: Map k a -> Set k

   containers	Data.Map.Strict.Internal

   The set of all keys of the map.

   keysSet (fromList [(5,"a"), (3,"b")]) == Data.Set.fromList [3,5]
   keysSet empty == Data.Set.empty
   

3. isProperSubsetOf :: Ord a => Set a -> Set a -> Bool

   containers	Data.Set

   (s1 `isProperSubsetOf` s2) indicates whether s1 is a proper subset of s2.

   s1 `isProperSubsetOf` s2 = s1 `isSubsetOf` s2 && s1 /= s2
   

4. isSubsetOf :: Ord a => Set a -> Set a -> Bool

   containers	Data.Set

   (s1 `isSubsetOf` s2) indicates whether s1 is a subset of s2.

   s1 `isSubsetOf` s2 = all (`member` s2) s1
   s1 `isSubsetOf` s2 = null (s1 `difference` s2)
   s1 `isSubsetOf` s2 = s1 `union` s2 == s2
   s1 `isSubsetOf` s2 = s1 `intersection` s2 == s1
   

5. powerSet :: Set a -> Set (Set a)

   containers	Data.Set

   Calculate the power set of a set: the set of all its subsets.

   t `member` powerSet s == t `isSubsetOf` s
   

   Example:

   powerSet (fromList [1,2,3]) =
   fromList $ map fromList [[],[1],[1,2],[1,2,3],[1,3],[2],[2,3],[3]]
   

6. isProperSubsetOf :: Ord a => Set a -> Set a -> Bool

   containers	Data.Set.Internal

   (s1 `isProperSubsetOf` s2) indicates whether s1 is a proper subset of s2.

   s1 `isProperSubsetOf` s2 = s1 `isSubsetOf` s2 && s1 /= s2
   

7. isSubsetOf :: Ord a => Set a -> Set a -> Bool

   containers	Data.Set.Internal

   (s1 `isSubsetOf` s2) indicates whether s1 is a subset of s2.

   s1 `isSubsetOf` s2 = all (`member` s2) s1
   s1 `isSubsetOf` s2 = null (s1 `difference` s2)
   s1 `isSubsetOf` s2 = s1 `union` s2 == s2
   s1 `isSubsetOf` s2 = s1 `intersection` s2 == s1
   

8. powerSet :: Set a -> Set (Set a)

   containers	Data.Set.Internal

   Calculate the power set of a set: the set of all its subsets.

   t `member` powerSet s == t `isSubsetOf` s
   

   Example:

   powerSet (fromList [1,2,3]) =
   fromList $ map fromList [[],[1],[1,2],[1,2,3],[1,3],[2],[2,3],[3]]
   

9. class ParseTime t

   time	Data.Time.Format

   The class of types which can be parsed given a UNIX-style time format string.

10. parseTimeM :: (MonadFail m, ParseTime t) => Bool -> TimeLocale -> String -> String -> m t

    time	Data.Time.Format

    Parses a time value given a format string. Missing information will be derived from 1970-01-01 00:00 UTC (which was a Thursday). Supports the same %-codes as formatTime, including %-, %_ and %0 modifiers, however padding widths are not supported. Case is not significant in the input string. Some variations in the input are accepted:

    • %z %Ez accepts any of ±HHMM or ±HH:MM.
    • %Z %EZ accepts any string of letters, or any of the formats accepted by %z.
    • %0Y accepts exactly four digits.
    • %0G accepts exactly four digits.
    • %0C accepts exactly two digits.
    • %0f accepts exactly two digits.
    For example, to parse a date in YYYY-MM-DD format, while allowing the month and date to have optional leading zeros (notice the - modifier used for %m and %d):

    Prelude Data.Time> parseTimeM True defaultTimeLocale "%Y-%-m-%-d" "2010-3-04" :: Maybe Day
    Just 2010-03-04
    

Page 73 of many | Previous | Next