A small remark:

on map, the rev_map function composed with rev (which are purely
function and tail-rec) may be often faster than a tail recursive version
of map on large list, especially if each function call
from map does some allocation, because the tail recursive version of map
does assignments and this cost a lot for the GC ...

I did some testing, and the timings where similar for both solution ...
which is not what I expected.

-- 
Christophe Raffalli
Université de Savoie
Batiment Le Chablais, bureau 21
73376 Le Bourget-du-Lac Cedex

tél: (33) 4 79 75 81 03
fax: (33) 4 79 75 87 42
mail: Christophe.Raffalli@univ-savoie.fr
www: http://www.lama.univ-savoie.fr/~RAFFALLI
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