There has been a recent discussion of ``Church encoding'' of lists and
the comparison with Scott encoding.
I'd like to point out that what is often called Church encoding is
actually Boehm-Berarducci encoding. That is, often seen
> newtype ChurchList a =
> CL { cataCL :: forall r. (a -> r -> r) -> r -> r }
(in http://community.haskell.org/%7Ewren/list-extras/Data/List/Church.hs )
is _not_ Church encoding. First of all, Church encoding is not typed
and it is not tight. The following article explains the other
difference between the encodings
http://okmij.org/ftp/tagless-final/course/Boehm-Berarducci.html
Boehm-Berarducci encoding is very insightful and influential. The
authors truly deserve credit.
P.S. It is actually possible to write zip function using Boehm-Berarducci
encoding:
http://okmij.org/ftp/ftp/Algorithms.html#zip-folds
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