Type Alias StateUnfolder<A, FoldState>

An unfolder where the types are tupled with some state FoldState. A function of the type

StateUnfolder<A, FoldState> = (pair: [Tree<A>, FoldState]) => TreeF<
  [A, FoldState],
  [Tree<A>, FoldState],
>
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Allows you to thread some state through the given tree.