Christian Maeder wrote:
My proposal would be to add a function like
\begin{code} replaceBy :: ([a] -> (b, [a])) -> [a] -> [b] replaceBy splt l = case l of [] -> [] _ -> let (ft, rt) = splt l in ft : replaceBy splt rt \end{code}
that takes a function "splt" that splits a non-empty list and returns a shorter list as second component (to ensure termination).
.... if we're in the business of proposing generalised search and replace I'd like to propose this one: http://haskell.org/pipermail/haskell-cafe/2007-July/028032.html which is along the general lines above but slightly more general. When I made that posting in 2007 I was hoping for name suggestions. In the absence of anythign better I suggest 'Data.List.transform' or the more whimsical 'Data.List.transmogrify'. I would also suggest a convenience function 'Data.List.replace' defined from it in the obvious way. I am also in agreement with 'groupsOf' (which I sometimes called 'chunksOf' but I like both names) proposed by Yitzchak. Will all that in mind I oppose this proposal, because whilst I fully support filling in some gaps in Data.List I don't think these are the best primitives. Jules