[Haskell-cafe] Removing alternate items from a list

[Stephen Tetley]

Hello

The regular list functionals - map, zip, foldl, foldr, filter, etc. -
all process the input list at "speed 1" - i.e. one element at a time.

As Ozgur Akgun has shown - consuming the list at "speed 2" gives a
very pleasant implementation - algorithmically:
"consume at speed 2, produce the new list with the first element of
the two and drop the second".

Trying to code an algorithm at "speed 1" with the list functionals
presents a significant hurdle towards clarity of exposition...

Best wishes

Stephen