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1. head :: forall (n :: Natural) a . Vec (n + 1) a -> a

   clash-prelude	Clash.Explicit.Prelude

   Extract the first element of a vector

   >>> head (1:>2:>3:>Nil)
   1
   

   >>> head Nil
   <interactive>:...
   • Couldn't match type ‘1’ with ‘0’
   Expected: Vec (0 + 1) a
   Actual: Vec 0 a
   • In the first argument of ‘head’, namely ‘Nil’
   In the expression: head Nil
   In an equation for ‘it’: it = head Nil
   

   # 448 "srcClashSized/Vector.hs"

2. head :: forall (n :: Natural) a . Vec (n + 1) a -> a

   clash-prelude	Clash.Explicit.Prelude.Safe

   Extract the first element of a vector

   >>> head (1:>2:>3:>Nil)
   1
   

   >>> head Nil
   <interactive>:...
   • Couldn't match type ‘1’ with ‘0’
   Expected: Vec (0 + 1) a
   Actual: Vec 0 a
   • In the first argument of ‘head’, namely ‘Nil’
   In the expression: head Nil
   In an equation for ‘it’: it = head Nil
   

   # 448 "srcClashSized/Vector.hs"

3. head :: forall (n :: Natural) a . Vec (n + 1) a -> a

   clash-prelude	Clash.Prelude

   Extract the first element of a vector

   >>> head (1:>2:>3:>Nil)
   1
   

   >>> head Nil
   <interactive>:...
   • Couldn't match type ‘1’ with ‘0’
   Expected: Vec (0 + 1) a
   Actual: Vec 0 a
   • In the first argument of ‘head’, namely ‘Nil’
   In the expression: head Nil
   In an equation for ‘it’: it = head Nil
   

   # 448 "srcClashSized/Vector.hs"

4. head :: forall (n :: Natural) a . Vec (n + 1) a -> a

   clash-prelude	Clash.Prelude.Safe

   Extract the first element of a vector

   >>> head (1:>2:>3:>Nil)
   1
   

   >>> head Nil
   <interactive>:...
   • Couldn't match type ‘1’ with ‘0’
   Expected: Vec (0 + 1) a
   Actual: Vec 0 a
   • In the first argument of ‘head’, namely ‘Nil’
   In the expression: head Nil
   In an equation for ‘it’: it = head Nil
   

   # 448 "srcClashSized/Vector.hs"

5. head :: forall (n :: Natural) a . Vec (n + 1) a -> a

   clash-prelude	Clash.Sized.Vector

   Extract the first element of a vector

   >>> head (1:>2:>3:>Nil)
   1
   

   >>> head Nil
   <interactive>:...
   • Couldn't match type ‘1’ with ‘0’
   Expected: Vec (0 + 1) a
   Actual: Vec 0 a
   • In the first argument of ‘head’, namely ‘Nil’
   In the expression: head Nil
   In an equation for ‘it’: it = head Nil
   

   # 448 "srcClashSized/Vector.hs"

6. head :: [a] -> Maybe a

   incipit-base	Incipit.List

   Return Just the head of a list.

7. head :: AList a -> a

   monad-par-extras	Control.Monad.Par.AList

   O(n) take the head element of an AList NB. linear-time, because the list might look like this:

   (((... `append` a) `append` b) `append` c)
   

8. head :: SymVal a => SList a -> SBV a

   sbv	Data.SBV.List

   head returns the first element of a list. Unspecified if the list is empty.

   >>> prove $ \c -> head (singleton c) .== (c :: SInteger)
   Q.E.D.
   

9. head :: SString -> SChar

   sbv	Data.SBV.String

   head returns the head of a string. Unspecified if the string is empty.

   >>> prove $ \c -> head (singleton c) .== c
   Q.E.D.
   

10. head :: forall (m :: Type -> Type) a . Monad m => Fold m a (Maybe a)

    streamly-core	Streamly.Data.Fold

    Deprecated: Please use "one" instead

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