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1. reifyTypeWithLocals_maybe :: DsMonad q => Name -> q (Maybe Type)

   th-desugar	Language.Haskell.TH.Desugar

   Like reifyWithLocals_maybe but for types and kinds. Note that a return value of Nothing might mean that the name is not in scope, or it might mean that the full type of the name cannot be determined. (Use reifyWithLocals_maybe if you really need to tell the difference.)

2. reifyWithLocals_maybe :: DsMonad q => Name -> q (Maybe Info)

   th-desugar	Language.Haskell.TH.Desugar

   Like reify from Template Haskell, but looks also in any not-yet-typechecked declarations. To establish this list of not-yet-typechecked declarations, use withLocalDeclarations. Returns Nothing if reification fails. Note that no inferred type information is available from local declarations; bottoms may be used if necessary.

3. tupleNameDegree_maybe :: Name -> Maybe Int

   th-desugar	Language.Haskell.TH.Desugar

   Extract the degree of a tuple Name. In addition to recognizing tuple syntax (e.g., ''(,,)), this also recognizes the following:

   • ''Unit (for 0-tuples)
   • ''Solo/'MkSolo (for 1-tuples)
   • ''TupleN (for N-tuples)
   In recent versions of GHC, ''() is a synonym for ''Unit, ''(,) is a synonym for ''Tuple2, and so on. As a result, we must check for ''Unit and ''TupleN in tupleDegree_maybe to be thorough. (There is no special tuple syntax for ''Solo/'MkSolo, but we check them here as well for the sake of completeness.)

4. unboxedSumNameDegree_maybe :: Name -> Maybe Int

   th-desugar	Language.Haskell.TH.Desugar

   Extract the degree of an unboxed sum Name. In addition to recognizing unboxed sum syntax (e.g., ''()), this also recognizes ''SumN# (for unboxed N-ary sum type constructors). In recent versions of GHC, ''Sum2# is a synonym for ''(), ''Sum3# is a synonym for ''(), and so on. As a result, we must check for ''SumN# in unboxedSumNameDegree_maybe to be thorough.

5. unboxedTupleNameDegree_maybe :: Name -> Maybe Int

   th-desugar	Language.Haskell.TH.Desugar

   Extract the degree of an unboxed tuple Name. In addition to recognizing unboxed tuple syntax (e.g., ''()), this also recognizes the following:

   • ''Unit# (for unboxed 0-tuples)
   • ''Solo#/'Solo# (for unboxed 1-tuples)
   • ''TupleN# (for unboxed N-tuples)
   In recent versions of GHC, ''(##) is a synonym for ''Unit#, ''() is a synonym for ''Tuple2#, and so on. As a result, we must check for ''Unit#, and ''TupleN in unboxedTupleNameDegree_maybe to be thorough. (There is no special unboxed tuple type constructor for ''Solo#/'Solo#, but we check them here as well for the sake of completeness.)

6. unionMaybeSubsts :: [Maybe DSubst] -> Maybe DSubst

   th-desugar	Language.Haskell.TH.Desugar.Subst

   No documentation available.

7. catMaybes :: [Maybe a] -> [a]

   HaXml	Text.XML.HaXml.XmlContent.Parser

   The catMaybes function takes a list of Maybes and returns a list of all the Just values.

   Examples

   Basic usage:

   >>> catMaybes [Just 1, Nothing, Just 3]
   [1,3]
   

   When constructing a list of Maybe values, catMaybes can be used to return all of the "success" results (if the list is the result of a map, then mapMaybe would be more appropriate):

   >>> import GHC.Internal.Text.Read ( readMaybe )
   
   >>> [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
   [Just 1,Nothing,Just 3]
   
   >>> catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
   [1,3]
   

8. forceMaybe :: Maybe a -> a

   MissingH	Data.Maybe.Utils

   Pulls a Just value out of a Maybe value. If the Maybe value is Nothing, raises an exception with error. Alias of fromJust.

9. forceMaybeMsg :: String -> Maybe a -> a

   MissingH	Data.Maybe.Utils

   Like forceMaybe, but lets you customize the error message raised if Nothing is supplied.

10. cast'Maybe :: Val a => Value -> Maybe (Maybe a)

    bson	Data.Bson

    No documentation available.

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