Class HList.HFoldr<G,V,L,R>

java.lang.Object
fj.data.hlist.HList.HFoldr<G,V,L,R>
Type Parameters:
G - The type of the function with which to fold.
V - The type of the value to be substituted for the empty list.
L - The type of the heterogeneous list to be folded.
R - The return type of the fold.
Enclosing class:
HList<A extends HList<A>>
public static final class HList.HFoldr<G,V,L,R> extends Object
The catamorphism over heterogeneous lists.

  • Field Details

    • foldRight

      private final F3<G,V,L,R> foldRight

  • Constructor Details

    • HFoldr

      private HFoldr(F3<G,V,L,R> foldRight)

  • Method Details

    • hFoldr

      public static <G,V> HList.HFoldr<G, V, HList.HNil, V> hFoldr()
      A fold instance for the empty list.
      Type Parameters:
      G - The type of the function with which to fold.
      V - The type of value that this fold returns.
      Returns:
      a fold instance for the empty list.

    • hFoldr

      public static <E, G, V, L extends HList<L>, R, RR, H extends HList.HFoldr<G,V,L,R>, PP extends HList.Apply<G,P2<E,R>,RR>> HList.HFoldr<G, V, HList.HCons<E,L>, RR> hFoldr(PP p, H h)
      A fold instance for a non-empty heterogeneous list
      Type Parameters:
      E - The type of the head of the list.
      G - The type of function to apply to the head of the list and the fold of its tail.
      V - The type of value to substitute for the empty list.
      L - The type of the tail of the list.
      R - The type of the fold of the tail of the list.
      RR - The return type of the fold.
      H - The type of the fold instance for the tail of the list.
      PP - The type of the given function application operator.
      Parameters:
      p - An operator that applies a function on the head of the list and the fold of its tail.
      h - A fold instance for the tail of the list.
      Returns:
      A fold instance for a non-empty heterogeneous list.

    • foldRight

      public R foldRight(G f, V v, L l)
      Folds a non-empty heterogeneous list.
      Parameters:
      f - A function with which to fold.
      v - The value to substitute for the empty list.
      l - The heterogeneous list to be folded.
      Returns:
      a value obtained by folding the given list with the given function.